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.

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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:

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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.

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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.

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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?