Introducing variables only for readability?

Question

Is it a good idea to introduce variables only for the sake of readability?

Example 1:

while(nameNode1.charAt(0) == nameNode2.charAt(0) && nameNode1.length() > 1 && nameNode2.length() > 1)
{
    nameNode1 = nameNode1.substring(1, nameNode1.length());
    nameNode2 = nameNode2.substring(1, nameNode2.length());
}

Example 2:

boolean letterFromBothNodesAreEqual_andNameHasMoreThanOneLetter = nameNode1.charAt(0) == nameNode2.charAt(0) && nameNode1.length() > 1 && nameNode2.length() > 1;

while(letterFromBothNodesAreEqual_andNameHasMoreThanOneLetter)
{
    nameNode1 = nameNode1.substring(1, nameNode1.length());
    nameNode2 = nameNode2.substring(1, nameNode2.length());
}

It might be an extreme example, but i think you get the idea.

I haven't seen this in code and i was wondering if this is a useful approach?

Thank You

Context: I'm trying to make the transition from college to Entry-Level-Developer and currently I'm focusing on clean-coding.

Answer 1

It's always better to make code readable, just don't over do it too much where it's a maintenance nightmare, although most clean code is easier to maintain.

I would introduce two new methods here instead of variables, where your code example would be:

while(letterFromBothNodesAreEqual() && nameHasMoreThanOneLetter())
{
    nameNode1 = nameNode1.substring(1, nameNode1.length());
    nameNode2 = nameNode2.substring(1, nameNode2.length());
}

It's a common readability refactor to extract boolean conditions into their own function with a name. If a person is reading your code and comes across some if with a bunch of conditions, they will wonder what the significance of it is, why is the branch needed or what it represents. The fields alone might not tell them the answer, but they might know what it represents if the condition had a name (the name of the function).

Answer 2

Apart from the fact that the variable name in your example is a bit too verbose, yes.

One thing that is important though is to remember to keep the scope of local variables as small as possible. So don't declare local variables at the start of the method if they're only going to be used in an if block further down.

Edit: And one more thing I've just noticed: your two examples are NOT equivalent. In the first scenario the expression is recalculated on every iteration, in the second one it isn't. In cases like this you need a helper method as explained by @NESPowerGlove instead of a variable.

Answer 3

Yes offcourse its a good practice to name variables according to there work or functionality in the program.Because in case in the future if someone else works on your code then it will be easier for him to understand otherwise it will give him a headache same happens while working on distributed program your co-workers must understand variables work by there name.

Answer 4

This question is quite subjective but the following holds true for all subjects. (I wanted to have a little fun with this answer)

private boolean isMoreReadable = true;
private boolean isEasyToMaintain = true;
private boolean isProperlyCommented = true;
private boolean isBugFree = true;

// This method checks if my co-workers are happy with my code
private boolean myCoWorkersHappyWithMyCode() {
    return isMoreReadable && isEasyToMaintain && isProperlyCommented && isBugFree;
}

if (myCoWorkersHappyWithMyCode()) {
    System.out.println("YES, you wrote good code so I don't see why not");
} else {
    System.out.println("NO, keep learning to better yourself");
}