locutus/golang/strings/Replace.js

Locutus other languages' standard libraries to JavaScript for fun and educational purposes

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.Replace = Replace;
function Replace(s, old, newStr, n) {
    //      discuss at: https://locutus.io/golang/strings/Replace
    // parity verified: Go 1.23
    //     original by: Kevin van Zonneveld (https://kvz.io)
    //          note 1: n is the number of replacements. If n < 0, no limit on replacements.
    //       example 1: Replace('oink oink oink', 'k', 'ky', 2)
    //       returns 1: 'oinky oinky oink'
    //       example 2: Replace('oink oink oink', 'oink', 'moo', -1)
    //       returns 2: 'moo moo moo'
    s = s + '';
    old = old + '';
    newStr = newStr + '';
    if (old === '') {
        return s;
    }
    if (n === 0) {
        return s;
    }
    if (n < 0) {
        // Replace all occurrences
        return s.replaceAll(old, newStr);
    }
    // Replace n occurrences
    let result = s;
    let count = 0;
    let pos = 0;
    while (count < n) {
        const idx = result.indexOf(old, pos);
        if (idx === -1) {
            break;
        }
        result = result.slice(0, idx) + newStr + result.slice(idx + old.length);
        pos = idx + newStr.length;
        count++;
    }
    return result;
}