Question

What is the ouput of the following code?

void loop(int num)

{

for(int i = 1; i < num; ++i)

{

for(int j = 0; j < 5; ++j)

{

cout << j;

}

}

}

int main()

{

loop(3);

return 0;

}

Answer 1

Starting from main, the function

loop(3)

is called.

So, the flow of the program moves to the function loop.

In the function loop there are two for loops:

1. for(int i = 1; i < num; ++i) (outer loop)

2. for(int j = 0; j < 5; ++j) (inner loop)

The outer loop will run for 2 times, for the value of i=1,2 and then the condition fails thus coming out of the loop.

The inner loop will run for 5 times, for the value of j=0,1,2,3,4 and then the condition fails.

Therefore, the execution is as follows:

outer loop iteration 1: value of i=1

inner loop iteration 1: value of j=0

output: 0

inner loop iteration 2: value of j=1

output: 01

inner loop iteration 3: value of j=2

output: 012

inner loop iteration 4: value of j=3

output: 0123

inner loop iteration 5: value of j=4

output: 01234

outer loop iteration 2: value of i=1

inner loop iteration 1: value of j=0

output: 012340

inner loop iteration 2: value of j=1

output: 0123401

inner loop iteration 3: value of j=2

output: 01234012

inner loop iteration 4: value of j=3

output: 012340123

inner loop iteration 5: value of j=4

output: 0123401234

Therefore, the output of the given code is 0123401234.