Check whether a string ends with some other string - JavaScript

In JavaScript, there are multiple ways to check if a string ends with another string. The most straightforward approach is using the built-in endsWith() method, though you can also implement custom solutions.

Using String.endsWith() (Recommended)

The endsWith() method is the standard way to check if a string ends with a specific substring:

const str1 = 'this is just an example';
const str2 = 'ample';

console.log(str1.endsWith(str2));        // true
console.log(str1.endsWith('temple'));    // false
console.log(str1.endsWith('example'));   // true

true
false
true

Custom Implementation Using substr()

You can create a custom function that extracts the ending portion of the string and compares it:

const str1 = 'this is just an example';
const str2 = 'ample';

const endsWith = (str1, str2) => {
    const { length } = str2;
    const { length: l } = str1;
    const sub = str1.substr(l - length, length);
    return sub === str2;
};

console.log(endsWith(str1, 'temple'));   // false
console.log(endsWith(str1, str2));       // true

false
true

Using slice() Method

Another approach uses slice() to extract the ending characters:

const checkEndsWith = (str1, str2) => {
    return str1.slice(-str2.length) === str2;
};

const str1 = 'this is just an example';
console.log(checkEndsWith(str1, 'ample'));    // true
console.log(checkEndsWith(str1, 'example'));  // true
console.log(checkEndsWith(str1, 'test'));     // false

true
true
false

Comparison of Methods

Conclusion

Use String.endsWith() for modern applications as it's the most readable and efficient method. For legacy browser support, the slice() approach offers a clean alternative to custom implementations.