Question

How many times will line 7 be executed when the following code is run?


String str = "rebellion";

int i = 0;

int j = str.length() - 1;

String result = "";

while (i < j)

{

result = str.substring(i, i + 1) + result + str.substring(j, j + 1);

i++;

j--;

}

System.out.println(result);
(Java)

Answer 1

Answer:

4 times

Explanation:

Required.

How many times will line 7 be executed?

Line 2 initialises i to 0

Line 3 subtracts 1 from the length of "rebellion" , the result of the subtraction is then saved in J

So:

j = 9 - 1

j = 8

From line 2 and line 3, we have that:

i = 0 and j = 8

Line 4 is an iteration that is repeated as long as i is less than j

Line 7 will be executed, for the first time as: i < j because 0 < 8

i is incremented to 1 and j is reduced to 7

Line 7 is then executed again, the second time because 1 < 7

i is incremented to 2 and j is reduced to 6

Line 7 is then executed again the third time because 2 < 6

i is incremented to 3 and j is reduced to 5

Line 7 is then executed again the fourth time because 3 < 5

i is incremented to 4 and j is reduced to 4

At this stage, line 7 will no longer be executed because I is no longer less than as 4 = 4.

Hence, number of execution is 4 times