In Java, loops are used to repeat a block of code as long as a specified condition is true. Loops are essential in Android development for tasks such as updating UI elements, processing data, or repeating actions. Java provides three main types of loops: for, while, and do-while.
1. For Loop in Java
The for loop is ideal when the number of iterations is known beforehand.
for (int i = 0; i < 5; i++) {
Log.d("LoopExample", "Value of i: " + i);
}Use Case in Android:
Loop through a list of items and display them in a RecyclerView.
2. While Loop in Java
The while loop is used when the condition needs to be checked before executing the block of code.
int i = 0;
while (i < 5) {
Log.d("LoopExample", "While loop i: " + i);
i++;
}Use Case in Android:
Poll for data while a network call is active or loading.
3. Do-While Loop in Java
The do-while loop will always execute the code block once, even if the condition is false.
int i = 0;
do {
Log.d("LoopExample", "Do-while i: " + i);
i++;
} while (i < 5);Use Case in Android:
Prompt user input at least once before checking validation.
Best Practices:
- Avoid infinite loops: ensure conditions are properly set.
- Prefer
forwhen iteration count is known. - Use
whileordo-whilewhen the condition depends on runtime logic. - Always test your loop logic with log outputs in Android Studio (
Log.d()).
Conclusion:
Understanding loops in Java is fundamental for Android developers. Whether you’re displaying lists, repeating animations, or validating inputs — mastering the for, while, and do-while loops gives you more control and flexibility in app development using Android Studio.