Another Javascript undefined error

Question

Another undefined error that I cant seem to get my head around. When I run the code my results include a undefined line:

No fault 06:44:46
Pkey 1 undefined 06:44:44
Pkey 1 Left 06:44:37
No fault Feb 09 12:28
Pkey 1 undefined Feb 09 12:28
Pkey 1 Right Feb 09 12:28

Please could someone point me in the right direction. Thanks

var a=p1.value;
var le=p9.value;
var re=p10.value;
if (le==true) {
            var x = " Left";
}
else if (re==true) {
            var x = " Right";

if (a>0) {
            var y = "Pkey"; 
            var result = y +" "+ a +" "+ x;
}
else if (a==0) {
            var result = "No fault"
return result;

`x` will be `undefined` if both `le` and `re` are anything other true. — Andy, Feb 10 '14 at 11:48

score 3 · Accepted Answer · answered Feb 10 '14 at 11:48

3

If neither the value of le or re evaluates to true, then x would be undefined.

As you only use == for comparison, remember that values like 0, null, empty string, and []all evaluate to false.

answered Feb 10 '14 at 11:48

kaspermoerch

16,127
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Thanks Kasper you were correct. – Duncan Feb 10 '14 at 13:40

score -2 · Answer 2 · answered Feb 10 '14 at 11:48

-2

The x should be declared before the statements.. and not inside the 'if' scopes

answered Feb 10 '14 at 11:48

ItayB

10,377
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That's good coding style, but makes no difference from JavaScript's perspective. – Quentin Feb 10 '14 at 11:51
Well it was worth to be down-voted because I had the opportunity to learn something new (actually js is not my native..) - just finished reading this related [issue about javascript variable scope](http://stackoverflow.com/questions/500431/javascript-variable-scope). Anyway as a developer in many programming languages it was the first think that catch my eyes and I think it might be helpful to stick the tradition of good coding style / readability code - especially when this is an enforcement in some other common programming languages. – ItayB Feb 11 '14 at 12:44

Another Javascript undefined error

2 Answers2