Problem with Variable declaration?

[Peter Sherwood]

Hello,

If I have the following simple piece of code:

var x = 1;
if (x === 1) {
    var URL = 'http://yahoo.com/';
    alert(URL);
} else {
    var URL = 'http://google.com/';
    alert(URL);
}

I get the following warning from Lint:

JavaScript Lint 0.3.0 (JavaScript-C 1.5 2004-09-24)
Developed by Matthias Miller (http://www.JavaScriptLint.com)

test.js
test.js(6): warning: redeclaration of var URL
    var URL = 'http://google.com/';
............^

0 error(s), 1 warning(s)

Obviously the variable has not been re-defined as it's at a different scope level. If I comment out the second URL declaration then the value is as expected "undefined".

Do you think this actually a bug? I use JTest (a java testing programme) and it performs similar checks. Similar java code would not produce a warning due to the level of scope.

Yes I could use code like the following:

var x = 1;
var URL;
if (x === 1) {
    URL = 'http://yahoo.com/';
    alert(URL);
} else {
    URL = 'http://google.com/';
    alert(URL);
}

However the problem still remains. What do you think?

regards

Pete

[Gabriel Barta]

Not sure what you mean when you say "However the problem still remains."  JavaScript Lint will not report an error for your revised code.

The warning is technically correct - unlike Java, JavaScript does not have block-level scoping so even though each of the variable declarations is written within the braces of the 'if' statement, it is actually a single variable which exists at function-level scope.

[Peter Sherwood]

Gabriel,

That's a fair reply, I was assuming the scoping was similar to Java. If it is at function level then the message is correct.

When I meant the problem still remains, I was referring to the warning message when I return the code to block level.

This piece of code shows it's not a problem.

if (1 == 1) {
  var newVar = 1;
}
if (2 == 2) {
alert(newVar);
}

You get the alert of 1.

thanks

Pete