JavaScript - check if string contains only digits

In this article, we would like to show you how to check if the string contains only digits in JavaScript.

Quick solution:

// ONLINE-RUNNER:browser;

let value = '123';

let result = /^\d+$/.test(value);

console.log(result);  // true

Practical example

In this example, we present how to check if the string contains only digits using regex.

Where:

• \d - stands for "digit" and matches any digit character (0-9),
• ^ - matches the beginning of the string,
• + - matches one or more of the preceding token (in our case one or more \d),
• $ - matches the end of the string.

Runnable example:

// ONLINE-RUNNER:browser;

let number = '123';

let text1 = 'A12';
let text2 = '1A2';
let text3 = '12A';

let empty = '';


let result1 = /^\d+$/.test(number);  // true
let result2 = /^\d+$/.test(text1);   // false
let result3 = /^\d+$/.test(text2);   // false
let result4 = /^\d+$/.test(text3);   // false
let result5 = /^\d+$/.test(empty);   // false

console.log(result1);  // true
console.log(result2);  // false
console.log(result3);  // false
console.log(result4);  // false
console.log(result5);  // false

See also

1. JavaScript - check if character is digit

References

1. RegExp.prototype.test() - JavaScript | MDN