javascript - Add values to an array

Question

How to add values to an empty array? I have tried the following but it is not working:

var student = [{}];
for (var i = 0; i < 5; i++) {
    student[i].name = i;
    student[i].id = "1";
    student.push(student[i]);
} 

var a = JSON.stringify(student);
alert(a);

It give output 6 time repeated last values not 5 time :

'[{"name":4,"id":"1"},{"name":4,"id":"1"},{"name":4,"id":"1"},{"name":4,"id":"1"},{"name":4,"id":"1"},{"name":4,"id":"1"}]'

Answer 1

var student = [{}];

This creates a javascript array containing one empty object

student[i].name = i;
student[i].id = "1";

For i = 0, this alters that empty object.

student.push(student[i]);

You then push that altered object to the array it already exists in. You now have two identical values in the array.

Two items after first push. This is repeated five times.

Pushing an item adds it to the array. There's usually no point in pushing an element that's already in the array. Create a new object and push that. The array doesn't have to be pre-populated with an empty object to modify.

var student = [];
for (var i = 0; i < 5; i++) {
    student.push({
        name: i,
        id: '1'
    });
}