how to prepend new item to array in typescript

Question

i need to prepend value in typescript objects array

Example if array is

[
   {'title':'this is post title1','content':'this is post content1'},
   {'title':'this is post title2','content':'this is post content2'},
   {'title':'this is post title3','content':'this is post content3'},
   {'title':'this is post title4','content':'this is post content4'},
   {'title':'this is post title5','content':'this is post content5'},
]

i want when i put new item in the first of this array like prepend in jQuery

[
   {'title':'this is new item title','content':'this is new item content'},
   {'title':'this is post title1','content':'this is post content1'},
   {'title':'this is post title2','content':'this is post content2'},
   {'title':'this is post title3','content':'this is post content3'},
   {'title':'this is post title4','content':'this is post content4'},
   {'title':'this is post title5','content':'this is post content5'},
]

thanks in advance

Same way as in JS. `typescript` tag is for TS-specific questions. — Estus Flask, Mar 09 '18 at 13:40
**.unshift()** TypeScript is a syntactic sugar of JavaScript. So You should google JavaScript a https://developer.mozilla.org/pl/docs/Web/JavaScript/Referencje/Obiekty/Array/unshift — Anton Temchenko, Mar 09 '18 at 13:43
Possible duplicate of [How can I add new array elements at the beginning of an array in JavaScript?](https://stackoverflow.com/questions/8073673/how-can-i-add-new-array-elements-at-the-beginning-of-an-array-in-javascript) — Mohammad Usman, Mar 09 '18 at 13:50
The example you gave is javascript. You should create a class in typescript for it. — Jeroen van Langen, Mar 09 '18 at 14:03

score 8 · Answer 1 · answered Mar 09 '18 at 13:40

You can use unshift to prepend items to an array:

const myArray = [ 2, 3, 4 ]

myArray.unshift(1)

console.log(myArray); // [ 1, 2, 3, 4 ]

You can find the docs here: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/unshift

score 6 · Answer 2 · answered Mar 09 '18 at 13:39

6

You can use the ... operator

Eg :

 let myArray = [ 1,2,3,4,5 ];
 myArray = [0, ...myArray];

answered Mar 09 '18 at 13:39

CharybdeBE

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Jeroen van Langen · Accepted Answer · 2018-03-09T13:58:25.467

2

It cannot be done with jquery, because it is functionality belongs to the javascript array object.

You could use the array function unshift() for that.

edited Mar 09 '18 at 13:58

answered Mar 09 '18 at 13:39

Jeroen van Langen

21,446
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score 2 · Answer 4 · answered Mar 09 '18 at 14:00

2

You can solve it with splice.

arr.splice(index, 0, item);

From another SO question

answered Mar 09 '18 at 14:00

Malcor

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how to prepend new item to array in typescript

4 Answers4