locutus/esm/php/array/prev.js

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

import { getEntryAtCursor, getPointerState } from "../_helpers/_arrayPointers.js";
export 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 = getPointerState(arr, false);
    if (!state || state.cursor === 0) {
        return false;
    }
    const previousCursor = state.cursor - 1;
    const entry = getEntryAtCursor(arr, previousCursor);
    if (!entry) {
        return false;
    }
    state.setCursor(previousCursor);
    return entry[1];
}