JavaScript Program to Validate String for Uppercase, Lowercase, Special Characters, and Numbers

Last Updated : 16 Jul, 2024

In this article, we are going to learn how can we check if a string contains uppercase, lowercase, special characters, and numeric values. We have given string str of length N, the task is to check whether the given string contains uppercase alphabets, lowercase alphabets, special characters, and numeric values or not. If the string contains all of them, then returns “true”. Otherwise, return “false”.

Examples:

Input : str = "GeeksforGeeks@123"
Output : trueput: Yes 
Explanation: The given string contains uppercase, lowercase, 
special characters, and numeric values.
Input : str = “GeeksforGeeks” 
Output : No 
Explanation: The given string contains only uppercase 
and lowercase characters.

Table of Content

Using Regular Expression
Using Array Methods
Using a Frequency Counter Object:
Using Array.prototype.every
Using Set to Check Character Categories

Using Regular Expression

We can use regular expressions to solve this problem. Create a regular expression to check if the given string contains uppercase, lowercase, special character, and numeric values as mentioned below:

Syntax:

regex = “^(?=.*[a-z])(?=.*[A-Z])(?=.*\\d)” + “(?=.*[-+_!@#$%^&*., ?]).+$”

where,

^ represents the starting of the string.
(?=.*[a-z]) represent at least one lowercase character.
(?=.*[A-Z]) represents at least one uppercase character.
(?=.*\\d) represents at least one numeric value.
(?=.*[-+_!@#$%^&*., ?]) represents at least one special character.
. represents any character except line break.
+ represents one or more times.

Match the given string with the Regular Expression using Pattern.matcher(). Print True if the string matches with the given regular expression. Otherwise, print False.

Example:This example shows the use of the above-explained approach.

JavaScript

// JavaScript Program to Check if a string contains
// uppercase, lowercase, special characters and
// numeric values
function isAllCharPresent(str) {
    let pattern = new RegExp(
        "^(?=.*[a-z])(?=.*[A-Z])(?=.*\\d)(?=.*[-+_!@#$%^&*.,?]).+$"
    );

    if (pattern.test(str))
        return true;
    else
        return false;
    return;
}

// Driver Code
const str = "#GeeksForGeeks123@";

console.log(isAllCharPresent(str));

Output

true

Using Array Methods

Convert the string to an array of characters. Utilize array methods like some() to check for uppercase, lowercase, special characters, and isNaN() to check for numeric values. Return the results in an object.

Example: In this example The function checkString analyzes a string for uppercase, lowercase, numeric, and special characters, returning an object indicating their presence. It's then tested with a sample string.

JavaScript

function checkString(str) {
  const chars = Array.from(str);

  const hasUppercase = chars.some(char => /[A-Z]/.test(char));
  const hasLowercase = chars.some(char => /[a-z]/.test(char));
  const hasNumeric = chars.some(char => !isNaN(char) && char !== ' ');
  const hasSpecial = chars.some(char => /[!@#$%^&*(),.?":{}|<>]/.test(char));

  return {
    hasUppercase,
    hasLowercase,
    hasNumeric,
    hasSpecial
  };
}

const result = checkString("HelloWorld123!");
console.log(result);

Output

{
  hasUppercase: true,
  hasLowercase: true,
  hasNumeric: true,
  hasSpecial: true
}

Using a Frequency Counter Object:

In this approach, we create an object to count the occurrences of each type of character (uppercase, lowercase, numeric, and special characters) in the string. Then, we check if each category has at least one occurrence.

JavaScript

function checkString(str) {
  const charCount = {
    uppercase: false,
    lowercase: false,
    numeric: false,
    special: false
  };

  for (const char of str) {
    if (/[A-Z]/.test(char)) {
      charCount.uppercase = true;
    } else if (/[a-z]/.test(char)) {
      charCount.lowercase = true;
    } else if (!isNaN(char) && char !== ' ') {
      charCount.numeric = true;
    } else if (/[!@#$%^&*(),.?":{}|<>]/.test(char)) {
      charCount.special = true;
    }
  }

  return charCount;
}

const result = checkString("HelloWorld123!");
console.log(result);

Output

{ uppercase: true, lowercase: true, numeric: true, special: true }

Using Array.prototype.every

In this approach, we will create a function that uses the every method to check if all characters in the string meet certain criteria: uppercase, lowercase, numeric, and special characters.

Example: In this example, we will use the every method to check each character in the string.

JavaScript

function isAllCharPresent(str) {
    const hasUppercase = [...str].some(char => /[A-Z]/.test(char));
    const hasLowercase = [...str].some(char => /[a-z]/.test(char));
    const hasNumeric = [...str].some(char => /\d/.test(char));
    const hasSpecial = [...str].some(char => /[!@#$%^&*()_+\-=[\]{};':"\\|,.<>/?]/.test(char));

    return hasUppercase && hasLowercase && hasNumeric && hasSpecial;
}

const str = "#GeeksForGeeks123@";
console.log(isAllCharPresent(str)); // Output: true

const str2 = "GeeksforGeeks";
console.log(isAllCharPresent(str2)); // Output: false
// Nikunj Sonigara

Output

true
false

Using Set to Check Character Categories

In this approach, we will use a Set to store the different types of characters found in the string. This way, we can easily check if the string contains at least one of each required character type.

Example: This example demonstrates how to use Set to check if a string contains uppercase, lowercase, numeric, and special characters.

JavaScript

function isAllCharPresent(str) {
    const charTypes = new Set();
    const specialCharacters = new Set(['!', '@', '#', '$', '%', '^', '&', '*', '(', ')', '_', '+', '-', '=', '[', ']', '{', '}', ';', ':', '"', '\\', '|', ',', '.', '<', '>', '/', '?']);

    for (const char of str) {
        if (/[A-Z]/.test(char)) {
            charTypes.add('uppercase');
        } else if (/[a-z]/.test(char)) {
            charTypes.add('lowercase');
        } else if (/\d/.test(char)) {
            charTypes.add('numeric');
        } else if (specialCharacters.has(char)) {
            charTypes.add('special');
        }
    }

    return charTypes.has('uppercase') && charTypes.has('lowercase') && charTypes.has('numeric') && charTypes.has('special');
}
const str1 = "#GeeksForGeeks123@";
console.log(isAllCharPresent(str1));

const str2 = "GeeksforGeeks";
console.log(isAllCharPresent(str2));

Output

true
false

Introduction to JavaScript

blalverma92

Improve

Article Tags :

JavaScript Program to Validate String for Uppercase, Lowercase, Special Characters, and Numbers

Using Regular Expression

Syntax:

Using Array Methods

Using a Frequency Counter Object:

Using Array.prototype.every

Using Set to Check Character Categories

Similar Reads

JavaScript Basics

JS Variables & Datatypes

JS Operators

JS Statements

JS Loops

JS Perfomance & Debugging

JS Object

JS Function

JS Array

Thank You!

What kind of Experience do you want to share?