JavaScript - test if string has postfix (suffix)

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
const hasPostfix = (text, prefix) => {
    if (prefix.length > text.length) {
        return false;
    }
    for (let i = prefix.length - 1, j = text.length - 1; i >= 0; --i, --j) {
        if (text[j] !== prefix[i]) {
            return false;
        }
    }
    return true;
};


// Usage example:

const text = 'This is example text.';

console.log(hasPostfix(text, ''));               // true
console.log(hasPostfix(text, 'text.'));          // true
console.log(hasPostfix(text, 'example text.'));  // true

console.log(hasPostfix(text, '123'));            // false
console.log(hasPostfix(text, '   '));            // false