修改数组就像在对象内部修改对象一样。正常的一般原则将在此处适用。
在以下示例中，最初在' companies '数组中，第一个元素是' Tesla'。但是在修改后，第一个元素更改为“ SolarCity ”，结果显示在输出中。
<html>
<body>
<script>
var res1 = "";
var res2 = "";
var obj = {
"name":"Elon musk",
"age":48,
"companies": [
"Tesla", "Spacex", "Neuralink"
]
}
for (var i in obj.companies) {
res1 += obj.companies[i] + "</br>"
}
document.write("Before change: " +" "+res1);
obj.companies[0] = "SolarCity";
for (var i in obj.companies) {
res2 += obj.companies[i] + "</br>"
}
document.write("After change:" +" "+res2);
</script>
</body>
</html>输出结果
Before change: Tesla Spacex Neuralink After change: SolarCity Spacex Neuralink