Javascript - [为什么?] 将变量分配给对象 [英] Javascript - [Why?] Assigning a variable to an object

问题描述

为什么当我将变量分配给对象并更改该变量时，它也会更改对象?例如:

Why is it that when I assign a variable to an object and make a change to that variable it also changed the objects? For example:

c = 26;
a = b = c;
a += 1;

a      // 27
b      // 26
c      // 26

但是

z = {};
x = y = z;
x.ab = 5; 

x      // Object {ab: 5}
y      // Object {ab: 5}
z      // Object {ab: 5}

为什么(在上面的例子中)y.ab 和 z.ab 存在?我只修改了 x 而不是 y 或 z.为什么在第一个示例中(使用整数)，当我更改 a 的值时，b 和 c 没有受到影响?>

Why (in the example above) does y.ab and z.ab exist? I only modified x not y or z. Howcome in the first example (with the integers), when I changed the value of a, b and c weren't affected?

推荐答案

当你将一个对象赋值给一个变量时，它只会引用原始对象，不会复制.所以所有的变量都指向同一个对象.

When you assign an object to a variable, it just makes a reference to the original object, it doesn't make a copy. So all the variables refer to the same object.

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