concat 的使用
concat() 方法用于合并两个或多个数组。此方法不会更改现有数组，而是返回一个新数组。如果省略了所有参数，则 concat 会返回调用此方法的现存数组的一个浅拷贝。
<script>var arr1 = ["k", "a", "i"];var arr2 = ["m", "o"];var arr3 = [3, 1, 3];var result1 = arr1.concat(arr2, arr3);console.log("result1----->", result1);var result2 = arr1.concat(arr2, arr3, "hello", 666);console.log("result2----->", result2);
</script>
手写 concat
<script>Array.prototype.kaimoConcat = function (...args) {let newArr = [...this];if (args.length === 0) {return newArr;}args.forEach((el) => {if (Array.isArray(el)) {newArr.push(...el);} else {newArr.push(el);}});return newArr;};var result3 = arr1.kaimoConcat(arr2, arr3);console.log("result3---kaimoConcat-->", result3);var result4 = arr1.kaimoConcat(arr2, arr3, "hello", 666);console.log("result4---kaimoConcat-->", result4);
</script>
