Goto Next Iteration in For Loop in Java

The ins and outs of loop control

A well-managed loop control enhances your program's performance. Java offers certain tools for loop flow control, namely: continue, break, and labels.

Understanding continue

The continue keyword is used in for, while, and do-while loops to jump to the next iteration, ignoring any subsequent code block in the current loop. Let's say, if a condition does not require the execution of the remaining loop, continue comes to the rescue.

for (int i = 0; i < list.size(); i++) {
    if (!list.get(i).isConditionMet()) {
        continue; // "I'll pass", said the loop, gracefully.
    }
    // Process the element
}


Note: Be cautious while defining your conditions to avoid an infinite loop or unnecessary skipping of the code block.

Meet break

The break keyword breaks the shackles and exits the loop entirely, disregarding its current state.

for(int i = 0; i < 10; i++) {
    if(someCondition(i)) {
        break; // "Break" free from the tyranny of the loop!
    }
    // Rest of the loop code
}


Using labels for complex loops

For nested loops, labels can be a lifesaver. They are great at controlling break and continue for outer loops.

outerLoop: // This is a label
for(int i = 0; i < 10; i++) {
    innerLoop:
    for(int j = 0; j < 10; j++) {
        if(someCondition(i, j)) {
            continue outerLoop; // "Continue" with the outer loop, the show must go on!
        }
        // Inner loop code
    }
    // Outer loop code
}


Labels make loop management easier, but remember to use them sparingly.

Know the pitfalls and follow best practices

Just like any competitive race, there are some bumps on the track. Here are some common issues developers often face and how you can dodge them:

Infinite loop – The never-ending race!

An improperly used continue can lead to an infinite loop if your condition never changes:

while(true) {
    if(someUnchangingCondition) {
        continue; // This creates a loop that's more infinite than the love for coffee!
    }
    // Code that may never execute
}


Labels – A road sign or a detour?

While helpful, labels can be more of a distraction if not used right. Use them sparingly and with relevant naming.

Nested loops – The rabbit hole!

Nested loops can look like a monster coding challenge. Opt for refactoring or breaking them into separate methods for better readability.

Unit Testing – The ultimate race practice!

It's always a good practice to have your code beat the stopwatch (or other test cases). It helps in uncovering unexpected behavior or logic errors within loops.