locutus/php/strings/substr_compare.js

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

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.substr_compare = substr_compare;
function substr_compare(mainStr, str, offset, length, caseInsensitivity) {
    //      discuss at: https://locutus.io/php/substr_compare/
    // parity verified: PHP 8.3
    //     original by: Brett Zamir (https://brett-zamir.me)
    //     original by: strcasecmp, strcmp
    //       example 1: substr_compare("abcde", "bc", 1, 2)
    //       returns 1: 0
    if (!offset && offset !== 0) {
        throw new Error('Missing offset for substr_compare()');
    }
    if (offset < 0) {
        offset = mainStr.length + offset;
    }
    if (length && length > mainStr.length - offset) {
        return false;
    }
    length = length || mainStr.length - offset;
    mainStr = mainStr.substr(offset, length);
    // Should only compare up to the desired length
    str = str.substr(0, length);
    if (caseInsensitivity) {
        // Works as strcasecmp
        mainStr = (mainStr + '').toLowerCase();
        str = (str + '').toLowerCase();
        if (mainStr === str) {
            return 0;
        }
        return mainStr > str ? 1 : -1;
    }
    // Works as strcmp
    return mainStr === str ? 0 : mainStr > str ? 1 : -1;
}