locutus/php/array/prev.js

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

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.prev = prev;
const _arrayPointers_ts_1 = require("../_helpers/_arrayPointers.js");
function prev(arr) {
    //      discuss at: https://locutus.io/php/prev/
    // parity verified: PHP 8.3
    //     original by: Brett Zamir (https://brett-zamir.me)
    //          note 1: Uses global: locutus to store the array pointer
    //       example 1: var $transport = ['foot', 'bike', 'car', 'plane']
    //       example 1: prev($transport)
    //       returns 1: false
    const state = (0, _arrayPointers_ts_1.getPointerState)(arr, false);
    if (!state || state.cursor === 0) {
        return false;
    }
    const previousCursor = state.cursor - 1;
    const entry = (0, _arrayPointers_ts_1.getEntryAtCursor)(arr, previousCursor);
    if (!entry) {
        return false;
    }
    state.setCursor(previousCursor);
    return entry[1];
}