Why using a variable name “temp” considered a bad practice?

Question

Whenever i put up a code for review from professional programmers they tend to point out that \"using a variable named temp is bad\" but no one seems to know why.

Why is

Answer 1

temp indeed doesn't mean anything useful. A better question is: does it have to?

Without knowing the context (how is it used in your code?), it's hard to say what it's for, and whether temp is a good name. If you use a variable often or non-locally, the name must be descriptive. A name like temp can be fine if you use it, say, three times in three adjacent lines.

void swapIntPointers(int *a, int *b) {
    int temp = *a;
    *a = *b;
    *b = temp;
}

It's immediately obvious what this function should do (from its name) and what it actually does (from its structure). In this specific case, I strongly prefer short (and automatically nondescript) names. I'd even say that temp may be a little too long here ;)

However:

• If you use the variable often, it's apparently important, and 'deserves' a better name.
• If you use the same variable in places in the function that are far apart (non-local), it helps programmers to 'remember' the meaning when you give it a recognizable name.