如何在JavaScript中清空数组?[副本]

ArrayList 在第一个方法之后被清空,因此将空数组分配给 Method2

let ArrayList = ['a', 'b', 'c', 'd', 'e', 'f'];

let Method1 = ArrayList; // Referenced arrayList by another variable 
ArrayList = []; // Empty the array 
console.log(Method1); // Output ['a','b','c','d','e','f']

console.log('ArrayList after Method1....!' , ArrayList)
// here an empty array is assinged to Method2
let Method2 = ArrayList; // Referenced arrayList by another variable 
ArrayList.length = 0; // Empty the array by setting length to 0
console.log(Method2); // Output []

= )接线员知道。

变量只是内存位置的绑定名称。

当我们通过 运算符,我们只改变变量指向的对象,我们不改变现有内存位置的实际数据,我们只是使变量不再指向它。

// Method1 now points to the same memory location as ArrayList
let Method1 = ArrayList;
// ArrayList variable now points to a new memory location containing an empty array
ArrayList = []; 
// Method1 is still pointing to the original memory location so the array is unaffected
console.log(Method1);

在第二个示例中,直接影响 ArrayList 是指通过改变 length 到 0

// point Method2 variable to the same location as ArrayList variable
let Method2 = ArrayList; 
// change the data stored at the location ArrayList is pointing to
ArrayList.length = 0; // Empty the array by setting length to 0
// Since Method2 is also pointing to that location, we see the empty array
console.log(Method2); // Output []