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Asked: 2020-04-19 19:08:09 +0800 CST 2020-04-19 19:08:09 +0800 CST

Add elements to an array of Objects

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How do I add elements to an array of objects in Typescript? According to what I think it should be as follows but for some reason it doesn't work.

OBJECT

conSubNet: Port[] = [{
    ip: '',
    pu: '',
    uu: '',
    bc: '',
    mm: '',
    host: '',
    reqHost: ''
}];

LINE WHERE I ADD A DATA

this.conSubNet[z].ip = this.octOne + ' . ' + this.octTwo + ' . ' + this.octThree + ' . ' + this.octFour;
array

1 Answers

  1. Best Answer

    It doesn't work because

    this.conSubNet[z]

    Select the existing item in the index z. If such an index does not exist, it returns undefined. Y undefined is not an object and does not support access to its inner elements using ..

    The solution is to assign an object to position [z]. Change your assignment to

    this.conSubNet[z] = { ip: this.octOne + ' . ' + this.octTwo + ' . ' + this.octThree + ' . ' + this.octFour };

    Note that if an element already exists at that position , that code replaces that element. If you are not sure that the array is empty, you should check it first:

    if( this.conSubNet[x] === undefined ) {
    this.conSubNet[z] = { ip: this.octOne + ' . ' + this.octTwo + ' . ' + this.octThree + ' . ' + this.octFour };
} else {
    this.conSubNet[z].ip = this.octOne + ' . ' + this.octTwo + ' . ' + this.octThree + ' . ' + this.octFour;
}
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