在javascript中对数组使用.push()非常不言自明,无论类型如何,推入数组的对象是指针(浅)还是实际对象( question...When )。
发布于 2011-12-29 04:43:58
这取决于你推的是什么。对象和数组作为指向原始对象的指针被推送。像数字或布尔值这样的内置原语类型被作为副本推送。因此,由于不会以任何方式复制对象,因此没有针对它们的深层或浅层复制。
下面是一个显示它的工作代码片段:
var array = [];
var x = 4;
let y = {name: "test", type: "data", data: "2-27-2009"};
// primitive value pushes a copy of the value 4
array.push(x); // push value of 4
x = 5; // change x to 5
console.log(array[0]); // array still contains 4 because it's a copy
// object reference pushes a reference
array.push(y); // put object y reference into the array
y.name = "foo"; // change y.name property
console.log(array[1].name); // logs changed value "foo" because it's a reference
// object reference pushes a reference but object can still be referred to even though original variable is no longer within scope
if (true) {
let z = {name: "test", type: "data", data: "2-28-2019"};
array.push(z);
}
console.log(array[2].name); // log shows value "test" since the pointer reference via the array is still within scope
https://stackoverflow.com/questions/8660901
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