The ^ at the start of the character class inverts the class, matching every character not included. Thereby this regular expression would only fail if the string contains upper-case letters somewhere. Still, the -cmatch is still needed.
Powershell: How to test if a string contains Uppercase or Lowercase
One way to verify for the uppercase letters is using the string library's isupper() function. If every character in current string is uppercase, this function returns True; otherwise, it returns False.
To do so, import the re library and install it if it isn't already installed. We'll use the regular expression "[A Z]+$" after importing the re library. If the string contains any characters other than uppercase characters, this will return False; otherwise, True will be returned.
If you pass a single string, the return value is the converted version of that string. If you pass a single-column table that contains strings, the return value is a single-column table of converted strings. If you have a multi-column table, you can shape it into a single-column table, as working with tables describes.
When testing for an empty string in a switch statement, it's important to use the comparisonstatement as shown in this example instead of the raw value ''. In a switch statement, the rawvalue '' also matches $null. For example:
Checks whether an array contains a value, an object contains a key, or a string contains a substring. The string comparison is case-sensitive. However, when testing if an object contains a key, the comparison is case-insensitive.
Helm includes the following string functions:abbrev,abbrevboth,camelcase,cat,contains,hasPrefix,hasSuffix,indent,initials,kebabcase,lower,nindent,nospace,plural,print,printf,println,quote,randAlpha,randAlphaNum,randAscii,randNumeric,repeat,replace,shuffle,snakecase,squote,substr,swapcase,title,trim,trimAll,trimPrefix,trimSuffix,trunc,untitle,upper,wrap, andwrapWith.
FLOAT64 values can be +/-inf or NaN.When an argument has one of those values, the result of the format specifiers%f, %F, %e, %E, %g, %G, and %t are inf, -inf, or nan(or the same in uppercase) as appropriate. This is consistent with howGoogle Standard SQL casts these values to STRING. For %T,Google Standard SQL returns quoted strings forFLOAT64 values that don't have non-string literalrepresentations.
"string argument" - The default depends on the content of the very first search string. (Remember that is used to delimit search strings.) If the first search string is a valid regular expression that contains at least one un-escaped meta-character, then all search strings are treated as regular expressions. Otherwise all search strings are treated as literals. For example, "51.4 200" will be treated as two regular expressions because the first string contains an un-escaped dot, whereas "200 51.4" will be treated as two literals because the first string does not contain any meta-characters.
/G:file - The default depends on the content of the first non-empty line in the file. If the first search string is a valid regular expression that contains at least one un-escaped meta-character, then all search strings are treated as regular expressions. Otherwise all search strings are treated as literals.
When the search string contains multiple words, separated with spaces, then FINDSTR will return lines that contain either word (OR).A literal search (/C:"string") will reverse this behaviour and allow searching for a phrase or sentence. A literal search also allow searching for punctuation characters.
Usually, we do not want all letters in a string converted into all lower or small case letters. Suppose we want the first letter of each word in a text to be in uppercase and rest all characters should be in lower case.
In this article, we explored the SQL UPPER function and SQL LOWER function to convert the characters in uppercase and lowercase respectively. We also create a custom function to convert first letter of each word in the text to capital letter.
SubscribeBlogJavaScript BooksContactif(typeof ez_ad_units!='undefined')ez_ad_units.push([[728,90],'codingbeautydev_com-box-2','ezslot_5',162,'0','0']);__ez_fad_position('div-gpt-ad-codingbeautydev_com-box-2-0');How to Check if a String Contains Only Letters and Numbers in JavaScriptBy Ayibatari Ibaba/ Last updated on September 5, 2022if(typeof ez_ad_units!='undefined')ez_ad_units.push([[468,60],'codingbeautydev_com-box-3','ezslot_7',163,'0','0']);__ez_fad_position('div-gpt-ad-codingbeautydev_com-box-3-0');#mc_embed_signupbackground:#fff;clear:left;width:100%;margin:auto#nl-imagewidth:100%;height:autoSubscribe to Coding Beauty NewsletterGain useful insights and advance your web development knowledge with weekly tips and tutorials from Coding Beauty. Over 2,000 developers subscribe.(function($)window.fnames=new Array();window.ftypes=new Array();fnames[0]='EMAIL';ftypes[0]='email';fnames[2]='LNAME';ftypes[2]='text';fnames[3]='ADDRESS';ftypes[3]='address';fnames[4]='PHONE';ftypes[4]='phone';fnames[5]='BIRTHDAY';ftypes[5]='birthday';fnames[1]='GIVEAWAY';ftypes[1]='text';fnames[7]='SOURCE';ftypes[7]='text'(jQuery));var $mcj=jQuery.noConflict(!0)1. The RegExp test() MethodTo check if a string contains only letters and numbers in JavaScript, call the test() method on this regex: /^[A-Za-z0-9]*$/. If the string contains only letters and numbers, this method returns true. Otherwise, it returns false.
The RegExp test() method searches for a match between the regular expression and a specified string.The / and / characters are used to start and end the regular expression.if(typeof ez_ad_units!='undefined')ez_ad_units.push([[300,250],'codingbeautydev_com-medrectangle-3','ezslot_1',164,'0','0']);__ez_fad_position('div-gpt-ad-codingbeautydev_com-medrectangle-3-0');
The ^ character matches the beginning of the string, while the $ character matches the end of the string.if(typeof ez_ad_units!='undefined')ez_ad_units.push([[468,60],'codingbeautydev_com-medrectangle-4','ezslot_2',165,'0','0']);__ez_fad_position('div-gpt-ad-codingbeautydev_com-medrectangle-4-0');The square brackets ([]) are used to match any one of multiple specified patterns. In our example, we specify three patterns: A-Z, a-z, and 0-9.A-Z matches any uppercase letter.
We can use the String match() method in place of RegExp test().if(typeof ez_ad_units!='undefined')ez_ad_units.push([[580,400],'codingbeautydev_com-banner-1','ezslot_4',167,'0','0']);__ez_fad_position('div-gpt-ad-codingbeautydev_com-banner-1-0');function onlyLettersAndNumbers(str) return Boolean(str.match(/^[A-Za-z0-9]*$/));const str1 = 'number60';const str2 = 'contains spaces';const str3 = 'has special characters [email protected]#$%^&';console.log(onlyLettersAndNumbers(str1)); // trueconsole.log(onlyLettersAndNumbers(str2)); // falseconsole.log(onlyLettersAndNumbers(str3)); // falseThe String match() method returns an array of all the matches of a regular expression in a string. If there are no matches, it returns null.const str1 = 'number60';const str2 = 'contains spaces';const str3 = 'has special characters [email protected]#$%^&';// [ 'number60', index: 0, input: 'number60', groups: undefined ]console.log(str1.match(/^[A-Za-z0-9]*$/));console.log(str2.match(/^[A-Za-z0-9]*$/)); // nullconsole.log(str3.match(/^[A-Za-z0-9]*$/)); // nullWe pass the result of match() to the Boolean constructor to convert it to a Boolean. Boolean() converts truthy values to true, and falsy values to false.
This method works because there are not both uppercase and lowercase versions of punctuation characters, numbers, or any other non-alphabetic characters. In other words, those characters will be identical whether or not they are uppercase or lowercase. On the contrary, letters will be different when you compare their lowercase and uppercase versions.
Beyond the English alphabet, this solution will also work for most Greek, Armenian, Cyrillic, and Latin characters. But, it will not work for Chinese or Japanese characters since those languages do not have uppercase and lowercase letters.
The PowerShell string Contains() method checks if a string contains the specified string and It performs the case-sensitive comparison to check string contains another word and returns true if the string contains the value else returns false.
In the above PowerShell script, we have used ToLower() method over the string object $str to convert it into lowercase and use the Contains method to check if the string contains the value.
In such a case, use PowerShell like operator with a wildcard character (*) to check if a string contains a specified string. It searches if a string contains the substring in it or not
This is the most popular approach to case-insensitive string comparisons in Python. The lower() method converts all the characters in a string to the lowercase, making it easier to compare two strings. The example code shows how the lower() method works.
Let's build a simple signup form with Angular and see how we can implement custom validation rules. Our form is going to have three input fields for the email address, password, and confirm password. The password requirements we want to fulfill are:Must be at least 8 characters longMust be alphanumeric, with at least one uppercase and one lowercase characterMust have at least one special characterPassword and Confirm Password must matchWe're going to validate these rules using Regular Expressions and give users visual feedback.I'm using the latest version of Angular, but you should be able to use the same code in previous releases. I'm assuming you have a basic understanding of Angular and Bootstrap, but even if you're new to Angular it shouldn't be hard to follow along. Before we get started, this is how the end result is going to look like.In this demo, we're going to use Bootstrap 4.6 and Bootstrap Icons 1.4 for the user interface. Feel free to use the UI framework of your choice.Getting StartedFirst, let's create a new Angular CLI project. Assuming you have Node.js, npm and Angular installed, execute the following command in your terminal (I'm on Windows and using PowerShell).ng new ng-password-validation-example --style=scss --routing=falseThis will create a new Angular project using SCSS styling, and no routing. Next, we install Bootstrap as our UI library. I'm using npm but you could use the package manager of your choice, like yarn.npm install --save bootstrapNext, we're going to import Bootstrap. I'm going to import the SCSS file directly, open src/styles.scss and add the following import:@import "bootstrap/scss/bootstrap";Alternatively, you could update your angular.json file and add it to the styles section. Note that Bootstrap is imported before the application styles, otherwise, your overrides won't work ?."styles": [ "node_modules/bootstrap/scss/bootstrap.scss" "src/styles.scss"]Now we need an icon pack. I'm going to use Bootstrap Icons, but you could use FontAwesome, Material Icons, or any other. To keep things simple, I'll import it via CDN. Open src/index.html and add the following link in the head section:Lastly, we need to import the Reactive Forms Module since we're going to build a reactive form. Open app.module.ts and import the module:import NgModule from "@angular/core";import BrowserModule from "@angular/platform-browser";import ReactiveFormsModule from "@angular/forms";import AppComponent from "./app.component";@NgModule( imports: [BrowserModule, ReactiveFormsModule], declarations: [AppComponent], bootstrap: [AppComponent])export class AppModule Great, we have all we need in place. Now let's talk about custom validators before we build the signup form.Building Custom ValidatorsAngular provides built-in validators, and they're great for common use cases. But they're not going to help us achieve our requirements. We need a custom validator that uses RegEx (regular expression) to check individual rules and report back to us. So our custom validator needs to accept a RegEx, and a validation error object to return. For instance, if we wanted to check whether a string contains a digit or not, we want to write something like this:patternValidator(/\d/, hasNumber: true ),Here, the method name is patternValidator. We're passing in the /\d/ regular expression and the second argument is the error object. Meaning if the target string didn't have a digit, the hasNumber error will be set on the form control. In the component template, we can check for control errors like control.hasError('hasNumber'). Nothing fancy here, basic stuff. Next, we'll create a class named PasswordValidators where we'll define our custom validation. Create the class manually, or use the Angular CLI:ng g class password-validatorsAll we need is a static method that accepts a regular expression and an error object. We're going to use the same method for each password rule, passing in different regular expressions. Here's the class definition:import AbstractControl, ValidationErrors, ValidatorFn from "@angular/forms";export class PasswordValidators constructor() static patternValidator(regex: RegExp, error: ValidationErrors): ValidatorFn return (control: AbstractControl): [key: string]: any => if (!control.value) // if the control value is empty return no error. return null; // test the value of the control against the regexp supplied. const valid = regex.test(control.value); // if true, return no error, otherwise return the error object passed in the second parameter. return valid ? null : error; ; We also need a validator to check whether the password and confirm password values match. Add the following method to the class: static MatchValidator(control: AbstractControl) const password: string = control.get("password").value; // get password from our password form control const confirmPassword: string = control.get("confirmPassword").value; // get password from our confirmPassword form control // if the confirmPassword value is null or empty, don't return an error. if (!confirmPassword?.length) return null; // if the confirmPassword length is this.isWorking = false; this.signupForm.enable(); , 1500); Nothing special going on, but let's see what we're doing here. First, we import FormControl, FormGroup, and Validators from @angular/forms. We also import the PasswordValidators class we just created. Then we define two properties on the component: submitted, and isWorking. The submitted property is used to check whether the form has been submitted or not. And the isWorking property is used to simulate an HTTP call (communicating with your API, creating an account, etc.). When you click the submit button, if the form is valid, we're going to disable the form, simulate a loading state, and reenable the form.The signupForm is a FormGroup composed of three controls: email, password, and confirmPassword. All three controls have a default value of null, this is important. If you were to set the default values to an empty string, the validators could behave unexpectedly. It's always best to set the default control values to null. The email control is simple and straightforward, it has two validators: email, and required. The confirmPassword control is simple too, it has two validators: required, and minLength(8). The password control is the interesting part. We're composing an array of validators using the Validators.compose method. The first two validators are built-in, required, and minLength. Then we define four custom validators using the static method we created. For each validation rule, we pass in a regular expression, and an error object to be set on the control if the RegExp didn't match. Right after the minLength validator, we define these rules:requiresDigit - the password must contain at least one digitrequiresUppercase - the password must contain at least one uppercase letterrequiresLowercase - the password must contain at least one lowercase letterrequiresSpecialChars - the password must contain at least one special characterLastly, we define a validator on the FormGroup itself for checking whether the passwords match or not:// control definitions removed for brevity.signupForm = new FormGroup( email: new FormControl(), password: new FormControl(), confirmPassword: new FormControl() , // FormGroup validators go here. validators: PasswordValidators.MatchValidator );So far so good, we have created the signup form and defined our custom validators. Before we continue to the component template, we need some helper methods. This step is not necessary, you could achieve the same thing right in the template code. But that would be messy and clutters your markup. We need a few helper methods to easily access form controls and get the status of validation errors. Add the following methods to the AppComponent class:// convenience getter for easy access to form controlsget f() return this.signupForm.controls;get passwordValid() return this.signupForm.controls["password"].errors === null;get requiredValid() return !this.signupForm.controls["password"].hasError("required");get minLengthValid() return !this.signupForm.controls["password"].hasError("minlength");get requiresDigitValid() return !this.signupForm.controls["password"].hasError("requiresDigit");get requiresUppercaseValid() return !this.signupForm.controls["password"].hasError("requiresUppercase");get requiresLowercaseValid() return !this.signupForm.controls["password"].hasError("requiresLowercase");get requiresSpecialCharsValid() return !this.signupForm.controls["password"].hasError("requiresSpecialChars");The first one is a convenient method for easily accessing form controls. The other methods, return a boolean for each validation rule. For instance, the requiresDigitValid method returns true if the password control doesn't have the requiresDigit error.Component TemplateLet's start with the layout, since we're using Bootstrap we need a basic layout to display our form. Open src/app/app.component.html and add the following markup: We have a fixed container, a row with some top margin, and a single column. Next, we create a reactive form element as you normally would: The form is bound to the signupForm FormGroup defined in the component class. And the submit event is bound to the onSubmit method, which we'll define later on. For each form control, we define a Bootstrap form-group element, like so: Email address Email address is required Email address is not valid Pretty straightforward, but let's examine the code. Each form control has a label and an input field. The input fields are bound to the FormGroup using the formControlName directive. For validation feedback, we use Bootstrap to toggle CSS classes. The [ngClass] directive is used to add the appropriate class to the input fields. The is-valid class is added if the form control is dirty, or if the form has been submitted, but there were no errors on the control. Similarly, the is-invalid class is added if there are errors on the form control. The invalid-feedback block is from Bootstrap, and we simply display error messages for individual errors using the ngIf directive. Great, that was easy. Now let's see the custom validation UI.Password Rules Validation UIWhat we want to do is, first check whether we have a password or not. If not, we want to display a required error message. If we do have a password, display the UI for our custom validation rules. This is the markup for the password control: Password Password is required Must be at least 8 characters long Must contain at least 1 digit Must contain at least 1 uppercase character Must contain at least 1 lowercase character Must contain at least 1 special character If you follow the inline comments you can see that it's all self-explanatory. But let's see what's going on here. The label and the input field are the same as the other controls, nothing special. Then we have the invalid-feedback block, which is the container for validation errors. First, we check whether we have a password or not:Password is requiredIf the password control is empty, we want to display this error message and hide the others. Following that, we have another block that wraps the custom validation rules UI. I'll include just one of them here: Must be at least 8 characters long The validation-rules block is only displayed if we have a password, but the requirements aren't met. For each validation rule, we use our helper methods to see if we have an error or not. And based on that, we display an icon and a message. If there's an error, we use the text-danger (from Bootstrap) class to have the error message in red. Otherwise, we use the text-success class to have the message in green. For the icons, we use the tag, and based on the validation status, we toggle the icon class name. Here's the complete code for the component template: Email address Email address is required Email address is not valid Password Password is required Must be at least 8 characters long Must contain at least 1 digit Must contain at least 1 uppercase character Must contain at least 1 lowercase character Must contain at least 1 special character Confirm password Confirm your password Password must be at least 8 characters long Passwords do not match isWorking ? 'Working on it...' : 'Create account' Now we need the submit handler. Add the onSubmit method to src/app/app.component.ts:onSubmit() this.submitted = true; if (this.signupForm.invalid) return; this.isWorking = true; this.signupForm.disable(); setTimeout(() => this.isWorking = false; this.signupForm.enable(); , 1500);First, we set the submitted property to true. This demo allows you to click the submit button to get the validation errors. Alternatively, you could disable the submit button until all validation requirements are met. Next, if the form is invalid (meaning there are errors on the form), the method returns, nothing happens. If the form is valid, we simulate an HTTP call. You'd call your API here, etc.Demo and Source CodeThat's it! Pretty cool. Angular is a powerful framework, and very flexible. You could use the same technique to implement your custom validation logic and enforce your business rules. If you want to learn more about form validation in Angular, have a look at these pages:Form ValidationReactive FormsCreating Async ValidatorsYou can find a demo to play with over here and see the complete code on StackBlitz.Updated at Sun Mar 21, 2021 Posted in Angular Tagged Tutorials QR Code Print Password Validation with Reactive Forms CloseAuthorArmin ZiaSoftware Engineer Leave a reply Comment body cannot be empty ? Name Email Website Please verify you are human ? Post comment ? Comment posted, thank you. It will go live after moderation. Reply body cannot be empty ? Name Email Website Please verify you are human ? 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