For loop inside function (newbie)

Question

I would like to have some variables that my for loop uses inside a function scope (not global).

I tried to wrap the for loop inside a function like this but it results in console error:

function() {
    var data = livingroomTableData;
    for(var i = data[0]; i < data[1]; i++) {
        var elemvalue = data[2] + format(i) + ".png";
        livingroomTableArray[i] = elemvalue;
    }
}

I would like the data variable to have the values of livingroomTableData only inside this for loop (not globally). In other loops I will input a different variable into the data variable.

Oh yes, and as you can probably tell, I'm a total newbie. :S

You have livingroomTableData then livingroomTableArray - are these different objects? — duncan
– duncan, Commented May 31, 2012 at 8:03
You’ve actually already achieved what you want in terms of data being local to the function. What console error are you getting? Note that, with your for loop conditions, unless data[0] is a number, i++ will cause an error after the code in the for loop runs for the first time. — Paul D. Waite
– Paul D. Waite, Commented May 31, 2012 at 8:03
+1 for being new and still knowing not to polute the global scope. — RichardTowers
– RichardTowers, Commented May 31, 2012 at 8:21

xdazz · Accepted Answer · 2012-05-31 08:03:34Z

1

There is only function scope in javascript, block scope does not exist, so you can't let the variable only inside the for loop. What you could do is to create a function scope.

Code example:

(function(livingroomTableData) {
    var data = livingroomTableData;
    //... the rest code
})(livingroomTableData);

answered May 31, 2012 at 8:03

xdazz

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2 Comments

xdazz Over a year ago

@PaulD.Waite Please read his code, he is simply wrapped the code in a function, which won't work.

Paul D. Waite Over a year ago

@xdazz: sure — with the code as he provided, his for loop won’t ever run.

RichardTowers · Accepted Answer · 2012-05-31 08:20:35Z

1

The big problem is this line:

for(var i = data[0]; i < data[1]; i++) {

That means, starting with i as the first element of the array, do the code in the loop, incrementing i by one at the end of each run until i is not less than the second element of data.

I'd rewrite it to show you a working version, but its not clear what you actually want to do.

edited May 31, 2012 at 8:20

answered May 31, 2012 at 8:04

RichardTowers

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Comments

Someth Victory · Accepted Answer · 2012-05-31 08:17:57Z

0

function() {
    for(var i = 0; i < livingroomTableData.length; i++) {
        var data = livingroomTableData[i];
        //your code here...
    }
}

answered May 31, 2012 at 8:17

Someth Victory

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