Is it better to check if a variable already has that value before assigning it?

user_18095197 0
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I'm sorry if it sounds like a stupid question, but: let's say that I have to change the bool variable 'a', based on a condition 'cond', but it could happens that 'a' already has the value I want to assign to it.

Now, should I do something like this:

// something that changes 'a'

if (cond) {
    a = true;
}

or should I check before if the variable 'a' is already true, like this:

// something that changes 'a'

if (cond) {
    if (!a) {
         a = true;
    }
}

Which way is faster? (and if there are differences in different programming languages)

algorithm
1 Answers

Use whatever is most clear to express your code's intent, which is usually the direct a = true;. A good compiler will optimize a boolean if (!a) { a = true; } into a = true; so the same performance can be expected.

Avoid premature optimization.

user_24103590
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