Javascript problem

Need a different pair of eyes on this, methinks.


<script>
function FindJump(gogo)
{
gogo='';
str=navigator.userAgent; // Agent is unique for our purposes
/* lotza working code edited out */
var isGek=str.indexOf("Gecko"); // Presumes is in all variants mentioned
if (isGek>=0) { gogo='PCbase.html'; }
var z = gogo;

// So, if not found, ASSuME we have mobile phone browser
if (z='') { gogo='Mobile.html'; }
document.writeln('3 gogo='+gogo+'|<BR>');
document.writeln('4 z='+z+'|<BR>');
return 'foo'+z+'||' //gogo;
};
</script>

<script>
str=navigator.userAgent; // Agent is unique for our purposes
document.writeln(str+"|<BR>");
// <a onTimeout="doOut(this, '/'+str', 'sass');return false;"></a><br>
var jmp=FindJump("hi");
document.writeln('jmp='+jmp);
</script>

/* on a PC, one sees: /* on a mobile phone, one sees:
3 gogo=PCbase.html| jmp=Mobile.html|
4 z=|
jmp=foo||

*/

For a mobile phone:
1) What is seen is reasonable, as contents of "str" had been previously
detected and the proper string was returned earlier in the function.

For a PC:
1) Line 3 shows that "z" was not empty; if it was, then "gogo"
would contain 'Mobile.html'
2) But line 4 then shows "z" as empty. WTF?
3) Likewise,the next line shows "z" as empty.

 

if (z=='')...

Equivalence testing is described here. There's the same problem
in C, where I occasionally type one "=" instead of two, when
doing an equivalence check.

http://javascript.about.com/od/decisionmaking/a/des02.htm

Your single "=", is an assignment statement.

Initially, I thought it might be a variable scoping problem,
until I caught that one.

Paul

 

Thanks!
I also see that an "extra" equals sign forces a type match as well;
not only for == but also for != .