JSFiddle - React, Tailwind, and code Playground

JavaScript

let arr = [1, 2, 3, 4]

const reverseArray = array => {
    for (let i = 0; i < array.length / 2; i++) {
        const temp = array[i];
        array[i] = array[array.length - 1 - i];
        array[array.length - 1 - i] = temp;
    }
    return array;
};

console.log(reverseArray(arr))