Question

I’m just wondering if it’s possible to declare multiple variables using a for loop in Javascript.

Example: I have 4 <article> elements whose Ids are article1 article2 article3 and article4. Instead of declaring each variable independently, I’d like to do it in a loop (as they use essentially the same code and I don’t want to repeat myself!).

Something like:

window.ready = function(){
    for (var i=1; i<=4; i++){

            var article[i] = document.getElementById("article" + i);

        }
}

The above returns an error with an unexpected [, so my syntax must be off (I’m very new to JS), but (a) is this on the right track and (b) will these be global variables if I run them in a window.ready function?

Answer 1

You cannot set a variable name with [ char. Using it, you will get an exception of javascript. You can use a List/Array to do this, try with Array class, something like:

window.ready = function() {

   var articles = new Array();

   for (var i=1; i<=4; i++){

      articles[i] = document.getElementById("article" + i);

   }
}

With Array class, you are not required to specify the lenght, but if you want, you can set it on the constructor.

var articles = new Array(4);

Another approach is use the push method to add elements on the array, for sample:

window.ready = function() {

   var articles = []; // define an empty array

   for (var i=1; i<=4; i++){

      articles.push(document.getElementById("article" + i));

   }
}