要将新值添加到现有数组，请使用JavaScriptsplice()方法。
您可以尝试运行以下代码以添加新值-
<html>
<head>
<title>JavaScript Array splice Method</title>
</head>
<body>
<script>
var arr = ["orange", "mango", "banana", "sugar", "tea"];
document.write("原始数组："+arr)
var newArr = arr.splice(2, 0, "water");
document.write("<br>After adding new element: " + arr );
</script>
</body>
</html>输出结果
原始数组：orange,mango,banana,sugar,tea After adding new element: orange,mango,water,banana,sugar,tea