C++ Nested Loops
Nested Loops
It is also possible to place a loop inside another loop. This is called a nested loop.
The "inner loop" will be executed one time for each iteration of the "outer loop":
Example
// Outer loop
for (int i = 1; i <= 2; ++i) {
cout << "Outer: " << i << "\n"; // Executes 2 times
// Inner loop
for (int j = 1; j <= 3; ++j) {
cout << " Inner: " << j << "\n"; // Executes 6 times (2 * 3)
}
}
Try it Yourself »
for (int i = 1; i <= 2; ++i) {
cout << "Outer: " << i << "\n"; // Executes 2 times
// Inner loop
for (int j = 1; j <= 3; ++j) {
cout << " Inner: " << j << "\n"; // Executes 6 times (2 * 3)
}
}
Multiplication Table Example
This example uses nested loops to print a simple multiplication table (1 to 3):
Example
for (int i = 1; i <= 3; i++) {
for (int j = 1; j <= 3; j++) {
cout << i * j << " ";
}
cout << "\n";
}
for (int j = 1; j <= 3; j++) {
cout << i * j << " ";
}
cout << "\n";
}
Result:
1 2 3
2 4 6
3 6 9
Try it Yourself »
2 4 6
3 6 9
Nested loops are useful when working with tables, matrices, or multi-dimensional data structures.