Mastering the Art of Loop Control: Understanding the C++ Continue Statement
Getting Started with C++ Fundamentals
Before diving into the world of loop control, make sure you have a solid grasp of these essential C++ concepts:
- C++ for loop
- C++ if…else statement
- C++ while loop
The Power of Continue: Skipping Iterations with Ease
In C++, the continue statement is a powerful tool that allows you to skip the current iteration of a loop and move on to the next one. The syntax is simple, but the impact is significant.
For Loops: A Perfect Example
Let’s explore how continue works in a for loop. Imagine you’re printing the values of a variable i
in each iteration. But, what if you want to skip a specific iteration? That’s where continue comes in.
Example 1: Skipping Iterations with For Loops
for (int i = 1; i <= 5; i++) {
if (i == 3) {
continue;
}
cout << i << endl;
}
In this example, when i
equals 3, the continue statement skips the current iteration and jumps to the update expression. As a result, the values 4 and 5 are printed in the next two iterations.
While Loops: Another Scenario
Now, let’s examine how continue works in a while loop. Suppose you’re prompting the user to enter numbers, and you want to calculate the total sum of positive numbers entered, but only up to a certain threshold.
Example 2: Continue with While Loops
int num;
int sum = 0;
while (true) {
cout << "Enter a number: ";
cin >> num;
if (num > 50) {
continue;
}
if (num < 0) {
break;
}
sum += num;
}
cout << "Total sum: " << sum << endl;
In this example, when the user enters a number greater than 50, the continue statement skips the current iteration and control flows back to the while condition. If the user enters a number less than 0, the loop terminates.
Nested Loops: A Deeper Dive
But what happens when continue is used with nested loops? The answer is simple: it skips the current iteration of the inner loop.
Example 3: Continue with Nested Loops
for (int i = 1; i <= 2; i++) {
for (int j = 1; j <= 3; j++) {
if (j == 2) {
continue;
}
cout << "i = " << i << ", j = " << j << endl;
}
}
In this example, when the continue statement executes, it skips the current iteration in the inner loop. As a result, the value of j = 2
is never displayed in the output.
Key Takeaway: Continue vs. Break
Remember, the continue statement only skips the current iteration, whereas the break statement terminates the loop entirely. Mastering the art of loop control requires understanding the nuances of these statements.