What is stored in str after the following code executes?

string str = "computer science";
int i = 0;
while (i < 8)
{
if (str. indexof("m") < i)
{
str = str. substring(0, 2) + str;
}
i += 2;
}

"CoCoComputer Science"

Explanation:

First let's understand how the loop works, then we'll see what it does.

The variable i is initialized to value 0.  Then inside the loop, it's incremented by 2 in each loop passage, while i < 8, so the loop will be processed with the following values of i: 0, 2, 4 and 6.  It will run a total of 4 times.

Let's examine the actions done during the FIRST loop:

(str equals "Computer Science", so indexOf('m') = 2, i = 0)

- if the index of 'm' within the string is < i  (index = 2, i = 0, FALSE)

does nothing

increases value of i by 2 (now i = 2)

Let's examine the actions done during the SECOND loop:

(str equals "Computer Science", so indexOf('m') = 2, i = 2)

- if the index of 'm' within the string is < i  (index = 2, i = 2,  FALSE)

does nothing

increases value of i by 2 (now i = 4)

Let's examine the actions done during the THIRD loop:

(str equals "Computer Science", so indexOf('m') = 2, i = 4)

- if the index of 'm' within the string is < i  ( index = 2,  i = 4, TRUE)

then str becomes "CoComputer Science"

increases value of i by 2 (now i = 6)

Let's examine the actions done during the FOURTH loop:

(str equals "CoComputer Science", so indexOf('m') = 4, i = 6)

- if the index of 'm' within the string is < i  (index = 4,  i = 6, TRUE)

then str becomes "CoCoComputer Science"

increases value of i by 2 (now i=8)

Loop ends because i = 8 (i < 8 becomes false)