In computer programming, the break statement is used to terminate the loop in which it is used.

The syntax of the break statement is:

break;

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Working of C++ break Statement

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Example 1: break with for loop

// program to print the value of i

#include <iostream>
using namespace std;

int main(){
    for (int i = 1; i <= 5; i++) {
        // break condition     
        if (i == 3) {
            break;
        }
        cout << i << endl;
    }

return 0;
}

Output

1
2

In the above program, the for loop is used to print the value of i in each iteration. Here, notice the code:

if (i == 3) {
    break;
}

This means, when i is equal to 3, the break statement terminates the loop. Hence, the output doesn’t include values greater than or equal to 3.

Note: The break statement is usually used with decision-making statements.

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Example 2: break with while loop

// program to find the sum of positive numbers
// if the user enters a negative numbers, break ends the loop
// the negative number entered is not added to sum

#include <iostream>
using namespace std;

int main(){
    int number;
    int sum = 0;

    while (true) {
        // take input from the user
        cout << "Enter a number: ";
        cin >> number;

        // break condition
        if (number < 0) {
            break;
        }

        // add all positive numbers
        sum += number;
    }

    // display the sum
    cout << "The sum is " << sum << endl;

    return 0;
}

Output

Enter a number: 1
Enter a number: 2
Enter a number: 3
Enter a number: -5
The sum is 6. 

In the above program, the user enters a number. The while loop is used to print the total sum of numbers entered by the user. Here, notice the code,

if(number < 0) {
    break;
}

This means, when the user enters a negative number, the break statement terminates the loop and codes outside the loop are executed.

The while loop continues until the user enters a negative number.

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break with Nested loop

When break is used with nested loops, break terminates the inner loop. For example,

// using break statement inside
// nested for loop

#include <iostream>
using namespace std;

int main(){
    int number;
    int sum = 0;

    // nested for loops

    // first loop
    for (int i = 1; i <= 3; i++) {
        // second loop
        for (int j = 1; j <= 3; j++) {
            if (i == 2) {
                break;
            }
            cout << "i = " << i << ", j = " << j << endl;
        }
    }

    return 0;
}

Output

i = 1, j = 1
i = 1, j = 2
i = 1, j = 3
i = 3, j = 1
i = 3, j = 2
i = 3, j = 3

In the above program, the break statement is executed when i == 2. It terminates the inner loop, and the control flow of the program moves to the outer loop.

Hence, the value of i = 2 is never displayed in the output.