Check string contains alphabets javascript

How can i check if a string contains any letter in javascript?

Im currently using this to check if string contains any numbers:

    jQuery(function($){
    $('body').on('blur change', '#billing_first_name', function(){
    var wrapper = $(this).closest('.form-row');
    // you do not have to removeClass() because Woo do it in checkout.js
    if( /\d/.test( $(this).val() ) ) { // check if contains numbers
    wrapper.addClass('woocommerce-invalid'); // error
    } else {
    wrapper.addClass('woocommerce-validated'); // success
    }
    });
    });

However i want it to see if it contains any letters.

asked May 1, 2020 at 20:08

4

You have to use Regular Expression to check that :-

var regExp = /[a-zA-Z]/g;
var testString = "john";
            
if(regExp.test(testString)){
  /* do something if letters are found in your string */
} else {
  /* do something if letters are not found in your string */
}

answered May 1, 2020 at 20:27

Arnab_DattaArnab_Datta

4645 silver badges8 bronze badges

5

/[a-z]/i.test(str)

Returns:

• true - if at least one letter is found (of any case, thanks to the /i flag)
• false - otherwise

/i - case insensitive flag

(/g - global flag (allows multiple matches) - in this scenario it would be at least redundant, if not harmful for the performance. Besides it sets the lastIndex property of regex (would be of concern if regex was used as a constant / variable and multiple tests were performed))

Note:

/[a-z0-9]/i.test(str)

would match any alphanumerical.

answered Mar 23, 2021 at 1:55

ellockieellockie

3,0546 gold badges35 silver badges38 bronze badges

If one wants to add support for non-ASCII letters also, then they may use Unicode property escapes.

const str_1 = '大阪';
const str_2 = '123';

console.log(/\p{L}/u.test(str_1)); // true
console.log(/\p{L}/u.test(str_2)); // false

answered May 23, 2021 at 19:24

brc-ddbrc-dd

8,0723 gold badges31 silver badges58 bronze badges

you can do this:

 export function containsCaracter(value) {
      return isNaN( +value / 1) || 
          value.includes('+') || value.includes('-') ;
    }

answered Mar 25 at 3:09

De BonheurDe Bonheur

5486 silver badges11 bronze badges

Check if String contains any Letters #

To check if a string contains any letters, use the test() method with the following regular expression /[a-zA-Z]/. The test method will return true if the string contains at least one letter and false otherwise.

Copied!
function containsAnyLetters(str) {
  return /[a-zA-Z]/.test(str);
}

console.log(containsAnyLetters('abc123')); // 👉️ true
console.log(containsAnyLetters('ABC')); // 👉️ true
console.log(containsAnyLetters('123')); // 👉️ false
console.log(containsAnyLetters(' ')); // 👉️ false

if (containsAnyLetters('hello')) {
  // 👇️ this runs
  console.log('✅ string contains a letter');
} else {
  console.log('⛔️ string does NOT contain a letter');
}

We used the RegExp.test method to check if a string contains at least 1 letter.

The test method returns true if the regular expression is matched in the string and false otherwise.

The forward slashes / / mark the beginning and end of the regular expression.

The square brackets [] are called a character class. In the character class we match 2 ranges:

• all lowercase letters a-z
• all uppercase letters A-Z

If you ever need help reading a regular expression, bookmark this regex cheatsheet from MDN.

Instead of using 2 ranges for lowercase and uppercase letters, we can also perform a case-insensitive match by using the i flag.

Copied!
function containsAnyLetters(str) {
  // 👇️ using the `i` flag
  return /[a-z]/i.test(str);
}

console.log(containsAnyLetters('A1')); // 👉️ true
console.log(containsAnyLetters('! !')); // 👉️ true

if (containsAnyLetters('abc123')) {
  // 👇️ this runs
  console.log('✅ string contains a letter');
} else {
  console.log('⛔️ string does NOT contain a letter');
}

Instead of using the range of uppercase letters A-Z, we used the i flag for case-insensitive search.

This achieves the same result, so it's a matter of personal preference which solution you find more readable and intuitive.

Further Reading #

• Check if String contains Special Characters in JavaScript
• Check if String contains Whitespace in JavaScript

How do you check if a string contains any letters in JavaScript?

How do you check if a string contains only alphabets and numbers in JavaScript?

How do I check if a string contains only characters?

How do you find a letter in a string?