javascript - 通过函数参数更改数组

Question

我需要将数组更改为在函数内创建的新数组。

function changeArr(a)
{
    a=["hello"];    // don't work
    //a.push("hello");    //works, but the real array pretty big (dont want copy)
}

var arr=[];

changeArr(arr);

console.log(arr); // should echo ["hello"]

Answer 1

看来您真正想做的就是在附加到它之前清除传递到函数中的数组:

function changeArr(a)
{        
    a.length = 0;      // clear the array here if you don't care about the prev. contents
    a.push("hello");   // this adds to the array that was passed in
}