Is it bad practice to use temporary variables to avoid typing?

Question

I sometimes use temporary variables to shorten the identifiers:

private function doSomething() {
    $db = $this->currentDatabase;
    $db->callMethod1();
    $db->callMethod2();
    $db->callMethod3();
    $db->...
}

Although this is a PHP example, I'm asking in general:

Is this bad practice? Are there any drawbacks?

Answer 1

This example is perfectly fine, since you are using it in functions/methods.

The variable will be unset right after the method/function ends - so there's not much of a memory leak or what.

Also by doing this, you "sort of" implemented DRY - don't repeat yourself.

Why write so many $this->currentDatabase when you can write $db. And what if you have to change $this->currentDatabase to some other values?

Answer 2

Actually, you're not trying to avoid typing (otherwise, you'd use a completion mechanism in your editor), but you're just making your function more readable (by using "abbreviations") which is a good thing.

Drawbacks will show up when you start doing this to avoid typing (and sacrifice readability)