Upload Validation for photos

Answer 1

Looks to me like it is going to compare the file extension against the first item in the list (.jpeg != .jpg) and return 0. This means it won't get a chance to try the second extension in the list.

Probably best to set a flag in the comparison and not return until all items in the extension list have been compared against the file extension.

Answer 2

Should be

for (i = 0; i < extensions.length; i++) {
    if (extensions[i] == final_ext) {
        return 1;
    }
}
return 0;

Note also that return immediately ends the current function, so putting a break after return is pointless.

Finally, if this Javascript is running on the client-side (i.e. in a web browser) keep in mind that the user may circumvent this (e.g. by using Firebug). You may wish to do checking at the server side too.

Answer 3

Your logic is wrong. This is what the loop should look like:

for (i = 0; i < extensions.length; i++) {
    if (extensions[i] == final_ext) {
        return 1;
    }
}
return 0;

Answer 4

Try a regular expression instead

function validate(x) {
    return /.(jpg|jpeg)$/ig.test(x);
}

Answer 5

Try something like this:

VALID_EXT = 'jpeg jpg';
function validate(x) {
  return +(VALID_EXT.split(/\s+/).indexOf(x.replace(/^.*\./,'').toLowerCase()) >= 0)
}
validate('file.jpeg');     // 1
validate('file.jpg');      // 1
validate('file.pic.jpg');  // 1
validate('file.gif');      // 0