array initialization in angular 2, Typescript

Question

when I am initializing array globally (outside the method) its working fine. but when I am initializing the same array inside the method its throwing error unexpected token. you can see into code for location of array. this is array calculateResult[] = [];

Screenshot of the error

private log: string ='result';
private kw: string = 'kw';
private frame: number = 0;
public finalResult[] = [];

//here this array is working fine
calculateResult[] = [];

DisplayResult(){

  //if i initialize this array here, it's throwing error
  // calculateResult[] = [];

  if(some_conditions_true){
     alert();
     this.log = '1SE0 070-2NC70' '\n';
     this.kw = '.37' '\n';
     this.frame = '71' '\n';

     this.calculateResult[0] = this.log;
     this.calculateResult[1] = this.kw;
     this.calculateResult[2] = this.frame;

     this.finalResult.push(this.calculateResult);

     for(i=0;i < this.finalResult.length;i++){
       console.log(this.finalResult[0][0]);
       console.log(this.finalResult[0][1]);
     }
}

What are '\n' s for? Don't you have compiler error for that? — Vega
– Vega, Commented Aug 21, 2017 at 20:02

Vega · Accepted Answer · 2017-08-31 09:32:06Z

3

The first declaration is considered as a class property, so it's correct.

The second one, is incorrect because it is inside the class method and thus should be either declared as

let calculateResult=[];

if you intend to declare a new array of that name,

either addressed as the class property declared above as

this.calculateResult = ...

So keep the first one: calculateResult = [];

If you keep it commented, this.calculateResult[0] will be undefined in the class method, you cannot refer to it.

edited Aug 31, 2017 at 9:32

answered Aug 21, 2017 at 18:49

Vega

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6 Comments

Mukul Sharma Over a year ago

@Faisal guys I tried both let calculateResult=[], let calculateResult [] = []; but I am getting error "14 caused by: Cannot set property '0' of undefined" i think because of this code. this.calculateResult[0] = this.log; this.calculateResult[1] = this.kw; this.calculateResult[2] = this.frame; ANY SUGGESTION ?

Vega Over a year ago

Uncomment calculateResult[] = [];, it's the correct one

Vega Over a year ago

You will need to post a new question, with the code and a possible plunker. It will be out of the scope of this question

Mukul Sharma Over a year ago

just a quick question, I am able to access values in console this way "console.log(this.finalResult[i][0]);" how can i access these 2D values in template.is there any alternative? this way is throwing error {{finalResult[i][0]}} . one Dimension is working {{finalResult[i]}} .

Vega Over a year ago

In which context do you access finalResult[i][0] ? in an ngfor?

|

Sajeetharan · Accepted Answer · 2017-08-21 18:47:17Z

1

You should initialize as

 DisplayResult(){
    this.calculateResult = [];
 }

answered Aug 21, 2017 at 18:47

Sajeetharan

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1 Comment

Mukul Sharma Over a year ago

thanks now its not throwing error. but it is not updating the array. if I am calling the method again, its not updating the values instead its just append the same values again. any suggestion?

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