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js数组 =号赋值改变一个,引发原数组改变问题
2022-07-19 16:55:00 【1default】
使用 = 直接赋值数组,修改新数组时会把原数组修改掉:
let oldArr = [
{group: 1, id: 2, name: "aa"},
{group: 2, id: 1, name: "bb"}];
let newArr2 = oldArr;
for (let i = 0; i < newArr2.length; i++) {
if (newArr2[i].id == 1) {
newArr2[i].name = "new";
break;
}
}
console.log(oldArr);
console.log(newArr2);
使用对象深拷贝,修改数组不影响原数组:
let oldArr = [
{group: 1, id: 2, name: "aa"},
{group: 2, id: 1, name: "bb"}];
let newArr2 = JSON.parse(JSON.stringify(oldArr)); //对象深拷贝,修改不影响之前的
for (let i = 0; i < newArr2.length; i++) {
if (newArr2[i].id == 1) {
newArr2[i].name = "new";
break;
}
}
console.log(oldArr);
console.log(newArr2);
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