java - Checking statement or assignation variable for performance? -

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what instruction takes more time between if() or variable initialization ?

will more efficient first check whether given variable has non-zero value , set if nonzero?

for example : boolean !

if (boolean)     boolean = false;

or directly : boolean = false;

most faster not check. depend on type of object being set (in case, boolean, "simple set"). particularly special objects have "simple compare" , "complex set" benefit checking first.

and if easy check , hard change, "set" function should check itself.

an exception shared memory between processors there lot of contention, since writing memory force caches of other processors flushed, takes time.


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