Question

Which is better in terms of performance for iterating an array?

(a) for(int i=0; i<100; i++)

(b) for(int i=99; i>=0; i–)

(c) for(int i=100; i<0; i++)

(d) for(int i=99; i>0; i++)

I had been asked this question in a job interview.

Origin of the question is Coding best practices topic in section Autoboxing & Miscellaneous of Java

Answer 1

Correct option is (b) for(int i=99; i>=0; i–)

The best I can explain: reverse traversal of array take half number cycles as compared to forward traversal. The other for loops will go in infinite loop.