angular2 create an associative array

Question

I would like to create an associative array in angular2 but havent found out a way yet

This is what i have tried

  onSubmit(){

let inputfield:any[]  = [];

for(var i=0; i<this.inspectionform.value["inputfileds"].length; i++){

 if(this.inspectionform.value["inputfileds"][i]["input"] != ""){
    //here i need help
    inputfield.push( i : this.inspectionform.value["inputfileds"][i]["input"]) //this returns a syntax error
  }

}

} So what am actually looking forward to have is to pass a key and value to the array

Something like

1:sdbhd//pass this to the array

In the for loop i have tried

//inside the for loop

     let arrayval = [];
    arrayval.push(this.inspectionform.value["inputfileds"][i]["input"])
    arrayval.push(i)

    inputfield.push(arrayval);

This creates a new object every time of this nature

0:njnf
1:1(value of i)

Solution 1

You can use a Map, but I'd opt into a plain object;

Demo

const mything = {}
mything.foo = 1
mything.foo === mything['foo'] // true
mything['bar'] = 1337;
mything.bar === 1337 // true
mything.foo-bar = 1 // ERROR: can't have dashes
mything['foo-bar'] = 1 // Works

In ES6, or any relatively modern browser, you can get all the keys by using Object.keys(mything). For older environments you're gonna have to loop over the keys using for ... in as demonstrated in this polyfill: https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Object/keys

Another thing you have to be careful of is having the previous item defined in your property chain. For example if you have

var foobar = {
  foo: { bar: 1 }
}

then you CAN do foobar.foo.bar.toString() to get "1", but if you try to do foobar.foo.bang.toString() you'll get an error cause bang is not defined on the foo object.

You can resolve this by doing a guard check like foobar.foo.bang && foobar.foo.bang.toString() which will only run the toString method if bang exists.

The easier way to do this would be to use lodash which gives you the _.get, and _.set which take care of the guards and the creation of the missing properties respectively.

Solution 2

Javascript does not have associate array, just use {} or new Map api

let xxxMap = new Map();

xxxMap.set('key1', 'value 1');

xxxMap.set('key2', 5);

console.log(xxxMap.get('key1'));

learn more from there: Map in Javascript