参考：js 数组和对象深拷贝的方法 https://www.cnblogs.com/webSnow/p/16134946.html
<!DOCTYPE html>
<html>
<body>
<h1>JavaScript 数组</h1>
<p>请单击按钮，以使用负数参数提取第三个和第四个元素。</p>
<button onclick="myFunction()">试一试</button>
<p id="demo1">P1</p>
<p id="demo2">P2</p>
<p id="demo3">P3</p>
<p id="demo4">P4</p>
<p id="demo5">P5</p>
<script>
function myFunction() {
//var fruits = ["Banana", "Orange", "Lemon", "Apple", "Mango"];
//var myBest = fruits.slice(0);
//var fruits = ["Banana", "Orange", "Lemon", "Apple", "Mango"];
var obj ={name:'jack', age:'30' }
var arr1=[];
arr1.push(obj);//1.数组1
var [ ...arr2 ] = arr1;//数组2(深拷贝，对象数组不行)
arr2[0].name ='peter';
var arr3 = arr1.slice(0);//数组3(深拷贝,对象数组不行)
arr3[0].name ='Tom';
document.getElementById("demo1").innerHTML = 'P1=' +arr1[0].name;
document.getElementById("demo2").innerHTML = 'P2=' +arr2[0].name;
document.getElementById("demo3").innerHTML = 'P3=' +arr3[0].name;
var arr4 = JSON.parse(JSON.stringify(arr1));//数组4(深拷贝,对象数组也可以)
arr4[0].name ='haha';
document.getElementById("demo4").innerHTML = 'P4=' +arr4[0].name;
var arr5 = copyObj(arr1);//数组4(深拷贝,对象数组也可以)
arr5[0].name ='gold';
document.getElementById("demo5").innerHTML = 'P4=' +arr5[0].name;
}
//对象数组深拷贝
function copyObj(obj) {
let res = {}
for (var key in obj) {
res[key] = obj[key]
}
return res
}
</script>
</body>
</html>