javascript undefined check not working

in javascript i am trying to check if a "key" has been defined on an array, and if it doesn't create it and assign a value 0 to it.

the following code is part of a large script and it is inside some loops that change the value of project, country and month

console.log(typeof total_searches[project][country][month]);
if(typeof total_searches[project][country][month] !== "number");
    total_searches[project][country][month] = 0;

but for some reason, when it goes over this 'if' for the second time (all the keys are defined by then) it evaluate开发者_如何学Cs as TRUE and assigns 0 to it.

The console.log shows "number" when doing a debug using chrome.

i also tried if(!(month in total_searches[project][country]))

but it still evaluates to TRUE and goes in

what am i doing wrong?

thanks

You got a nasty sneaky semicolon after the if.

if(typeof total_searches[project][country][month] !== "number"); // <-- here

!== also does a type match as well. try just !=

You have a semicolon after your if-statement, which is seen as the true-statement. So the next line is always executed as it is seen as 'just' another line of code.