General For Loops in Java

Introduction

• The lecture introduces general for loops in Java.
• General format of a for loop consists of:
  • Initialization: Executed once at the start.
  • Test: Determines if the loop should continue.
  • Increment: Modifies the variable after each loop iteration.

Basic For Loop Structure

• Example: for (initialization; test; increment)
• Initialization example: int i = 0
  • This sets up the loop variable.
• Test example: i < 10
  • Checks if the loop should continue.
• Increment example: i++
  • Modifies the loop variable after each run.

Examples of General For Loops

Countdown Program

• Task: Count down from 10 to 0.
• Code: for (int i = 10; i >= 0; i--) { System.out.println(i); }
• Explanation:
  • Starts with i = 10.
  • Tests if i is greater than or equal to 0.
  • Decrements i by 1 each iteration (i--).

Counting By Twos

• Task: Count by twos up to 100.
• Code: for (int i = 0; i <= 100; i += 2) { System.out.println(i); }
• Explanation:
  • Starts with i = 0.
  • Tests if i is less than or equal to 100.
  • Increments i by 2 each iteration (i += 2).

Modifying the Increment

• Example: Change increment from 2 to 3 for counting by threes.
• Code: for (int i = 0; i <= 100; i += 3) { System.out.println(i); }
• Explanation:
  • This makes the loop count by threes.

Conclusion

• General for loops offer flexibility with initialization, test, and increment steps.
• Allow for various counting patterns and control structures in Java programming.