Hey friends ! please explain me this code below and say me why output is 1121231234

Question

#include <iostream>
using namespace std;

int main() {
for (int i=1;i<=4;i++)
for(int j=1;j<=i;j++)
cout<<j;
return 0;
}

//output is 1121231234

Answer 1

Akash Pal

There's no slight error in the OP's code. Each for loop has one single statement in its scope and adding brace just make it more readable.

Answer 2

The first loop works first with initial value i = 1 and the loops works till I equal to 4. Inside that Another loop with initial value j = 1 and works till j less than or equal to i. First i = 1, the inner loop will be 1 to 1 printing value of j as 1.
Then the value of i increases to 2, th inner loop works printing values from 1 to 2 and so on till I equal to 4.
There is a slight error in your code.
The correct code.
#include <iostream>
using namespace std;

int main() {
for (int i=1;i<=4;i++){
for(int j=1;j<=i;j++){
cout<<j;
}
}
return 0;
}

//output is 1121231234