Field inside a variable dynamically?

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3

Follow the code below:

Javascript:

var img1 = false;
var img2 = true;

var img =  "img"+1;      //Resultado da variavel img é "img1".
                         //Como converter string para variável ?
                         //Exemplo: "img1" para img1

      if (img == false) //Errado ----> "img1" == false
      {                 //Certo -----> img1 == false ou seja false = false

      }

Some solution ?

javascript variables
  • 2

    Why don’t you use a array? It’s so much better and you don’t need this gambit..

  • 1

    You can give a concrete example of what you need to do?

  • 1

    Hi @bigown, can you believe

3 answers

4


If you want to insist on it you can do something like this:

var img1 = false;
var img2 = true;
var img = eval("img" + 1);
if (!img) console.log("ok");

But avoid using the eval(). The right thing to do is with a array:

var img = [false, true];
var img = img[0];
if (!img) console.log("ok");

I put in the Github for future reference.

Depending on the context another solution may be more appropriate.

I switched the img == false for !img if you have any doubt about it read that question.

  • You can also use string-casting - which is much safer: var img1 = 'hello'; var nome = "img"; console.log(window[''+nome+1]) (but more hammer still ;D)

  • 1

    @Moshmage tb, it’s all gambiarra, the array is the right solution.

  • Yes. It will be what he wants but not what he asked :P

  • Hi @bigown, helped me a lot. Array is very useful.

1

Instead of doing so uses array

vetor = new Array(false,true); //declarando e iniciando a array
var img = vetor[0]; //atribuindo o valor da posição 0 da array para a variavel 
if(img == false) {
    // ...
}

1

I suppose you need a code like that:

function foobar() {
   this.img1 = false;
   this.img2 = true;

   var img = this['img'.concat(1)];
   if (img == false) {
       alert("Falso!");
   }
   else {
       alert(img);
   }
}
new foobar();

If in a global context (outside of a function), you can exchange thisfor window. The function concat() will perform the concatenation, generating a1.

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