Question

2. Which of the following is an infinite loop?
a) int i = 5; for (int a=0; i < 20; a--)
b) int a = 5; while (a<20) a++;
c) for (a=0; a<20; a++) { }
d) for (int a = 2; a<20; a= a+2)​

Answer 1

Answer:

• Option a is the correct answer for the problem.

Explanation:

a)

int i = 5;

for (int a = 0; i < 20; a--) { }

In this co‎de, we can see that the value of 'i' is never incremented. So, the condition i < 20 remains true always. Thus the loop runs forever.

b)

int a = 5;

while (a < 20)

a++;

Here, the value of a is increasing which means the condition given inside brackets ultimately becomess false after some time. So the loop terminates.

c)

for(int a = 0; a < 20; a++) { }

This is quite similar to previous option. The value of a keeps increasing and the loop terminated when a becomes equal to 20.

d)

for (int a = 2; a < 20; a = a + 2) { }

This co‎de is similar to option c. Value of a increases by 2 and finally the loop terminates.