Javascript check if password contains letters and numbers
Checking for numbers and lettersSometimes situations arise ( suppose a user id, password or a code) when the user should fill a single or more than one field with alphabet characters (A-Z or a-z) and numbers (0-9) in an HTML form. You can write a JavaScript form validation script to check whether the required field(s) in the HTML form contains only letters and numbers. Show
Javascript function to check if a field input contains letters and numbers only
To get a string contains only letters and numbers (i.e. a-z, A-Z or 0-9) we use a regular expression /^[0-9a-zA-Z]+$/ which allows only letters and numbers. Next the match() method of string object is used to match the said regular expression against the input value. Here is the complete web document.+ Flowchart: HTML Code
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View the example in the browser Practice the example online See the Pen letters-numbers-field-1 by w3resource (@w3resource) on CodePen. file_download Download the validation code from here. Other JavaScript Validation :
Previous: JavaScript: HTML Form validation - checking for Floating point numbers JavaScript: Tips of the DaySpread operator const user = { name: 'Owen', age: 21 }; const admin = { admin: true, ...user }; console.log(admin); It's possible to combine objects using the spread operator .... It lets you create copies of the key/value pairs of one object, and add them to another object. In this case, we create copies of the user object, and add them to the admin object. The admin object now contains the copied key/value pairs, which results in { admin: true, name: "Owen", age: 21 }. Ref: https://bit.ly/323Y0P6 JavaScript : HTML Form validation - checking for passwordLast update on August 19 2022 21:51:07 (UTC/GMT +8 hours)Sometimes a password validation in a form is essential. You can create a password in different ways, it's structure may be simple, reasonable or strong. Here we validate various type of password structure through JavaScript codes and regular expression.
Following code blocks contain actual codes for the said validations. We have kept the CSS code part common for all the validations. CSS Code:
To check a password between 7 to 16 characters which contain only characters, numeric digits, underscore and first character must be a letterTo validate the said format we use the regular expression ^[A-Za-z]\w{7,15}$, where \w matches any word character (alphanumeric) including the underscore (equivalent to [A-Za-z0-9_]). Next the match() method of string object is used to match the said regular expression against the input value. Here is the complete web document. HTML Code:
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View the example in the browser To check a password between 6 to 20 characters which contain at least one numeric digit, one uppercase and one lowercase letterTo validate the said format we use the regular expression ^(?=.*\d)(?=.*[a-z])(?=.*[A-Z]).{4,8}$. Next the match() method of string object is used to match the said regular expression against the input value. Here is the complete web document. HTML Code:
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View the example in the browser To check a password between 7 to 15 characters which contain at least one numeric digit and a special characterTo validate the said format we use the regular expression ^^(?=.*[0-9])(?=.*[[email protected]#$%^&*])[[email protected]#$%^&*]{7,15}$. Next the match() method of string object is used to match the said regular expression against the input value. Here is the complete web document. HTML Code:
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View the example in the browser To check a password between 8 to 15 characters which contain at least one lowercase letter, one uppercase letter, one numeric digit, and one special characterTo validate the said format we use the regular expression ^(?=.*\d)(?=.*[a-z])(?=.*[A-Z])(?=.*[^a-zA-Z0-9])(?!.*\s).{8,15}$. Next the match() method of string object is used to match the said regular expression against the input value. Here is the complete web document. HTML Code:
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View the example in the browser Previous: JavaScript: HTML Form - Credit Card Number validation JavaScript: Tips of the DaySpread operator const user = { name: 'Owen', age: 21 }; const admin = { admin: true, ...user }; console.log(admin); It's possible to combine objects using the spread operator .... It lets you create copies of the key/value pairs of one object, and add them to another object. In this case, we create copies of the user object, and add them to the admin object. The admin object now contains the copied key/value pairs, which results in { admin: true, name: "Owen", age: 21 }. Ref: https://bit.ly/323Y0P6 How do you check if a string contains only alphabets and numbers in JavaScript?The RegExp test() Method
To check if a string contains only letters and numbers in JavaScript, call the test() method on this regex: /^[A-Za-z0-9]*$/ . If the string contains only letters and numbers, this method returns true . Otherwise, it returns false .
What is the RegEx for password?Search Results: 102 regular expressions found.. How do you check if a character is alphanumeric in JS?Syntax. if ((character >= '0' && character <= '9') || (character >= 'a' && character <= 'z') || (character >= 'A' && character <= 'Z')){. // character is alphanumeric.. }else{. // character is not alphanumeric.. How do you validate a password?How to validate password strength using a regular expression. The password length must be greater than or equal to 8.. The password must contain one or more uppercase characters.. The password must contain one or more lowercase characters.. The password must contain one or more numeric values.. |