Sleep Function Example in Java

Introduction

Sleep Function is a classic Java console program that demonstrates the concept with complete source code and sample output. Practical numeric and utility programs — primes, factorial, palindrome and similar classics.

This tutorial walks through the program line by line, explains how the logic works, and highlights best practices you can apply in your own code.

Definition

Sleep causes the current thread to suspend execution for a specified period. This is an efficient means of making processor time available to the other threads of an application or other applications that might be running on a computer system.

Syntax

Thread.sleep(Sleep_time);

Sleep Function Example Program

public class SleepFunctionDemo {
    public static void main(String args[])
        throws InterruptedException {
        String[] str = {
            "This is statement 1",
            "This is statement 2",
            "This is statement 3",
            "This is statement 4"
        };
        for (int i = 0;i < str.length;i++) {
            Thread.sleep(4000);
            System.out.println(str[i]);
			System.out.println("After 4 seconds....");

        }
    }
}

Sample Output

This is statement 1
After 4 seconds....
This is statement 2
After 4 seconds....
This is statement 3
After 4 seconds....
This is statement 4
After 4 seconds....

When to use

Use this sleep function example when learning or revising core Java syntax.

How it works

1. Execution begins in the main method — the JVM calls this method when you run the class.

2. String[] str = { updates a variable used in the calculation or output.

3. for (int i = 0;i < str.length;i++) { updates a variable used in the calculation or output.

4. A println / print call writes text to the console — part of the sample output below.

5. A println / print call writes text to the console — part of the sample output below.

6. Compare your console output with the sample output for Sleep Function to confirm the program behaves correctly.

Best Practices

• Use meaningful variable and class names that describe their purpose.
• Compile and run the program locally — modify values to see how output changes.
• Read compiler errors carefully; they usually point to the exact line to fix.

Common Mistakes

• Copying code without understanding each line — practice by changing one statement at a time.
• Mismatching the public class name and the .java filename.
• Forgetting semicolons at the end of statements.