java - Is it more efficient to declare a variable inside a loop, or just to reassign it? -

java - Is it more efficient to declare a variable inside a loop, or just to reassign it? -

while writing loops confused 1 should choose. example,

int sum; for(int i=0; i<10; i++) { sum=0; ... .... }

or

for(int i=0; i<10; i++) { int sum=0; ... .... }

say, variable required in loop. there no need of in later part of program. need value of variable sum 0 @ origin of loop. 1 improve practice? re-initializing variable @ start of loop or re-declaring it? 1 more efficient?

if declare variable outside of loop , not utilize past loop, compiler move declaration within loop.

that means there no reason compare efficiency here, since end same exact code jvm run 2 approaches.

so next code:

int sum; for(int i=0; i<10; i++) { sum=0; }

... becomes after compilation:

for(int = 0; < 10; i++) { int sum = 0; }

java performance loops initialization declaration