js数组乱序

const arrScrambling = (arr) => {
		        for (let i = 0; i < arr.length; i++) {
		      const randomIndex = Math.round(Math.random() * (arr.length - 1 ));
			  console.log(randomIndex);
		      [arr[i], arr[randomIndex]] = [arr[randomIndex], arr[i]];
		    }
		    return arr;
		}
		console.log(arrScrambling(['666','777','888','999']))