我只是想知道如果你做这样的事情是否会降低速度或效率:
I am just wondering if there would be any loss of speed or efficiency if you did something like this:
int i = 0;
while(i < 100)
{
int var = 4;
i++;
}
声明 int var
一百次.在我看来好像会有,但我不确定.这样做会更实用/更快吗:
which declares int var
one hundred times. It seems to me like there would be, but I'm not sure. would it be more practical/faster to do this instead:
int i = 0;
int var;
while(i < 100)
{
var = 4;
i++;
}
或者它们在速度和效率方面是否相同?
or are they the same, speedwise and efficiency-wise?
局部变量的栈空间通常在函数作用域内分配.所以循环内部不会发生堆栈指针调整,只是将 4 分配给 var
.因此,这两个代码段具有相同的开销.
Stack space for local variables is usually allocated in function scope. So no stack pointer adjustment happens inside the loop, just assigning 4 to var
. Therefore these two snippets have the same overhead.
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