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

Check if String contains a Character #

Use the String.includes[] method to check if a string contains a character, e.g. if [str.includes[char]] {}. The include[] method will return true if the string contains the provided character, otherwise false is returned.

Copied!
const str = 'Hello world';
const char = 'e';

console.log[str.includes[char]]; // 👉️ true

if [str.includes[char]] {
  // 👉️ string contains the character
}

We used the String.includes method to determine if the character is contained in the string.

This works with special characters as well, e.g. emojis:

Copied!
const str = 'Hello world 🐔';
const char = '🐔';

console.log[str.includes[char]]; // 👉️ true

if [str.includes[char]] {
  // 👉️ string contains the character
}

If you need to perform a case insensitive check, for whether a character is contained in a string, convert the string and the character to lowercase when calling String.includes.

Copied!
const str = 'Hello world';
const char = 'L';

// 👇️ true
console.log[str.toLowerCase[].includes[char.toLowerCase[]]];

if [str.toLowerCase[].includes[char.toLowerCase[]]] {
  // 👉️ string contains the character
}

We performed a case-insensitive check by converting the string and the character to lowercase when calling the includes method.

Alternatively, you can use the String.indexOf method.

Use the String.indexOf[] method to check if a string contains a character, e.g. if [str.indexOf[char] !== -1] {}. The indexOf method will return the index of the character in the string or -1 if the character is not contained in the string.

Copied!

  

const str = 'Hello world';
const char = 'l';

// 👇️ 2
console.log[str.indexOf[char]];

if [str.indexOf[char] !== -1] {
  // 👉️ string contains the character
}

We used the indexOf method to check if a string contains a character.

If there is no match, the String.indexOf method returns -1.

Our if statement checks if the indexOf returned a value other than -1. If it did, the character is contained in the string.

Which approach you pick is a matter of personal preference. I'd go with the includes method as I find it more direct and intuitive.

Further Reading #

• Check if String contains Special Characters in JavaScript
• Remove Special Characters from a String in JavaScript
• Check if String contains only Letters and Numbers in JS
• Check if String contains only Letters and Spaces in JS
• Check if String contains only Latin Letters in JavaScript
• Check if String contains only Digits in JavaScript
• Check if String contains only Spaces in JavaScript
• Check if String contains only Letters in JavaScript
• Check if a String is all Uppercase in JavaScript
• Check if a String ends with a Number in JavaScript
• Check if String starts with Substring in JavaScript
• Check if String contains any Letter in JavaScript

How do you check if a string contains only letters?

How do you check if the string contains a word in JavaScript?