Question

Is there a way to change the source of an HTML image using javascript based on variables? I am thinking of something like this:

var image = 1;

if(image=1) {
    document.getElementById('myImage').src = "images/one.png";
} else if(image=2) {
    document.getElementById('myImage').src = "images/two.png";
} else {
    window.alert("You have a weird variable value");
}

Please tell me how I can get this to work using an if…then or switch statement.

Answer 1

= is an assignment. An assignment statement evaluates as itself. So if(image=1) means “assign 1 to image, then if 1 is true…”. (1 is always a true value).

To compare two values use === (or == if you want type munging).

if (image === 1) {

and

} else if (image === 2) {