CODEWITHSUNDEEP
javascript
agconti
agconti

Reputation: 18123

How to initialize a variable before it's value is decided?

I have a basic for loop where I determine the value, 'left' or 'right', of a variable called animationDirection.

How can I initialize this variable before the loop so that it can be defined with in it?

I've tried initializing it to undefined, by using var animationDirection = undefined; but this is frowned upon by javascript linter.

I've settled on the code below that defines animationDirection in the loop logic, but this seems like a bad idea because I'm initializing the variable with var twice.

Any ideas on how to better define the variable?

for (var i = 0; i < $selected.length; i++) {

    if (i < ($selected.length / 2)) {
        var animationDirection = 'left';
    } else {
        animationDirection = 'right';
    }

    $($selected[i])
        .css(animationDirection, animationOffset)
        .velocity(animation, animationConfig);
}

Upvotes: 0

Views: 69

Answers (2)

JLRishe
JLRishe

Reputation: 101730

Like this:

var animationDirection,
    i;

for (i = 0; i < $selected.length; i += 1) {

    if (i < ($selected.length / 2)) {
        animationDirection = 'left';
    } else {
        animationDirection = 'right';
    }

    $($selected[i])
        .css(animationDirection, animationOffset)
        .velocity(animation, animationConfig);
}

Douglas Crockford's JSLint requires that variables be declared at the top of a function (not sure what lint you're using).

Here's a more concise approach that avoids the for-loop semantics (assuming here that $selected is a jQuery object) and makes the question of where to declare your variable much simpler:

$selected.each(function(i, e) {
    var animationDirection = (i < ($selected.length / 2)) ? "left" : "right";
    $(e).css(animationDirection, animationOffset)
        .velocity(animation, animationConfig);
});

Upvotes: 1

milagvoniduak
milagvoniduak

Reputation: 3254

How about?

for (var i = 0; i < $selected.length; i++) {
    $($selected[i])
        .css(i < ($selected.length / 2) ? 'left': 'right' , animationOffset)
        .velocity(animation, animationConfig);
}

Upvotes: 0

Related Questions