javascript – Cannot read property push of undefined when combining arrays

javascript – Cannot read property push of undefined when combining arrays

You get the error because order[1] is undefined.

That error message means that somewhere in your code, an attempt is being made to access a property with some name (here its push), but instead of an object, the base for the reference is actually undefined. Thus, to find the problem, youd look for code that refers to that property name (push), and see whats to the left of it. In this case, the code is

if(parseInt(a[i].daysleft) > 0){ order[1].push(a[i]); }

which means that the code expects order[1] to be an array. It is, however, not an array; its undefined, so you get the error. Why is it undefined? Well, your code doesnt do anything to make it anything else, based on whats in your question.

Now, if you just want to place a[i] in a particular property of the object, then theres no need to call .push() at all:

var order = [], stack = [];
for(var i=0;i<a.length;i++){
    if(parseInt(a[i].daysleft) == 0){ order[0] = a[i]; }
    if(parseInt(a[i].daysleft) > 0){ order[1] = a[i]; }
    if(parseInt(a[i].daysleft) < 0){ order[2] = a[i]; }
}

This error occurs in angular when you didnt intialise the array blank.
For an example:

userlist: any[ ];
this.userlist = [ ]; 

or

userlist: any = [ ];

javascript – Cannot read property push of undefined when combining arrays

order is an Object, not an Array().

push() is for arrays.

Refer to this post

Try this though(but your subobjects have to be Arrays()):

var order = new Array();

// initialize order; n = index
order[n] = new Array();

// and then you can perform push()
order[n].push(some_value);

Or you can just use order as an array of non-array objects:

var order = new Array();

order.push(a[n]);