Adding multiple items to an array using unshift

Question

I'm using unshift to add data to the beginning of an array

x.done(function(data) {
    data.unshift({ "data": {
        "number": "default",
        "description": "Account Default"
    } });
});

But it's giving me Uncaught TypeError: data.unshift is not a function

Although, I have used unshift before, and it works fine. I cannot work out what the issue is with this one.

I was also trying to add a second array inside data but this was returning a different error (I think I got the syntax wrong)

data.unshift({ "data": {
    "number": "default",
    "description": "Account Default"
},
{
    "number": "default",
    "description": "Account Default"
} });

below it, I use for(var i in data) {to loop through. it's JSON data — CJSF
– CJSF, Commented Feb 12, 2021 at 8:56
Oh, I've just seen it's not returning the same format. It looks like this 01234: {data: {…}, seq: "4", customer: "1234", display: "Number 01234", number: "01234", …} so data is inside another key — CJSF
– CJSF, Commented Feb 12, 2021 at 9:00

khizerrehandev · Accepted Answer · 2021-02-12 09:19:17Z

1

var data = [{
    "data": {
        "number": "default",
        "description": "Account Default"
    }
}];


data.unshift({
    "data": {
        "number": "default",
        "description": "new Data 1"
    }
})

data.unshift({
    "data": {
        "number": "default",
        "description": "new Data 2"
    }
});

// 3) [{…}, {…}, {…}] results 3

answered Feb 12, 2021 at 9:19

khizerrehandev

1,57717 silver badges15 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Shuvo · Accepted Answer · 2021-02-12 09:02:16Z

0

unshift works only with Array. But to add data at the beginning of an object, you can use ES6 spread syntax:

data = {
         { "data": {
            "number": "default",
            "description": "Account Default"
           } 
         }, 
         ...data
      }

answered Feb 12, 2021 at 9:02

Shuvo

1,2939 silver badges18 bronze badges

Comments

Jimmie · Accepted Answer · 2021-02-12 09:11:45Z

0

Since unshift only works with the Array type, are you certain that data is in fact of type Array? You could for example check this with the Array.isArray() method:

x.done(function(data) {
    console.log(Array.isArray(data));
});

Regarding your second problem it is indeed just a syntax error.

edited Feb 12, 2021 at 9:11

answered Feb 12, 2021 at 9:03

Jimmie

12 bronze badges

Collectives™ on Stack Overflow

Adding multiple items to an array using unshift

3 Answers 3

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related