What is for loop in java and how to implement it?
While programming, if a situation arises where you specifically know how many times you want to iterate a particular block of statements in your code, go for a “for” loop. In this article let’s learn about how to implement for loop in Java Programming Language.
The topics covered in this article are as follows:
- What is for loop?
- Flow diagram
- Syntax
- Example of for loop
- Java nested for loop
- Example of Java nested for loop
- Pyramid example: Case 1
- Pyramid example: Case 2
Let’s begin!
What is for loop?
Programmers usually use loops to execute a set of statements. the loop is used when they need to iterate a part of the programs multiple times. It is particularly used in cases where the number of iterations is fixed!
For a better understanding, let me give you a pictorial representation!
Flow diagram
Here, after initialization, the condition that you have assigned in the code is scanned, in case the condition is true, it would increment/decrement (according to your code) the value, and again iterate the code according to the condition that you have assigned. But, if your condition is false, it will exit the loop.
After this theoretical explanation, let me show you the syntax of the for loop!
Syntax
for (statement 1; statement 2; statement 3) {
// code block to be executed
}The syntax is pretty simple. It goes as follows
Statement 1: condition before the code block is executed
Statement 2: specifies the condition for execution of the code
Statement 3: condition once the code has been executed
To make things clearer, let us implement the above-explained syntax in Java code.
Example of for loop
The code written below depicts how for loop is implemented in Java Language
public class MyClass {
{
public static void main(String[] args) {
{for (int i = 0; i < 5; i++) {
System.out.println(i);
}
}
}}I have taken a simple code to get you all acquainted with the concept of for loop. Inside the for loop, there are three statements that I have talked about in the previous segment. I hope you can now relate to them easily!
- Firstly, Int i=0 is the initialization of an integer variable whose value has been assigned to 0.
- Secondly, i<5 is the condition that I have applied in my code
- Thirdly, i++, means that I want the value of my variable to be incremented.
After understanding the working of for loop, let me take you to another concept, that is Java nested for loop!
Java nested for loop
If you have a for loop inside a for loop, you have encountered a Java nested for loop. The inner loop executes completely when the outer loop executes.
I am presenting an example to show you the working of a Java nested for loop.
Example
A Java code for a nested for loop:
public class Example{
public static void main(String[] args) {
for(int i=1;i<=3;i++){
for(int j=1;j<=3;j++){
System.out.println(i+" "+j);
}
}
}
}Output:
1 1
1 2
1 3
2 1
2 2
2 3
3 1
3 2
3 3
Now that you have understood the concept of a nested for loop, let me show you a very famous example that you might have heard of! The pyramid examples!
Pyramid Example: Case 1
public class PyramidExample {
public static void main(String[] args) {
for(int i=1;i<=5;i++){
for(int j=1;j<=i;j++){
System.out.print("* ");
}
System.out.println();//new line
}
}
}Output:
*
* *
* * *
* * * *
* * * * *
Moving on with the next example.
Pyramid Example: Case 2
package MyPackage;
public class Demo {
public static void main(String[] args) {
int term=6;
for(int i=1;i<=term;i++){ for(int j=term;j>=i;j--){
System.out.print("* ");
}
System.out.println();//new line
}
}
}Output:
* * * *
* * * *
* * *
* *
*
I am sure that you would be familiar with these two patterns.
Thus we have come to an end of this article. If you wish to learn more, check out Java Training by Edureka, a trusted online learning company. Edureka’s Java J2EE and SOA training and certification course are designed to train you for both core and advanced Java concepts along with various Java frameworks like Hibernate & Spring.
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Do look out for other articles in this series that will explain the various other aspects of Java.
1. Object Oriented Programming
5. Java String
6. Java Array
8. Java Threads
9. Introduction to Java Servlets
11. Exception Handling in Java
12. Java Tutorial
14. Java Programs
15. Kotlin vs Java
16. Dependency Injection Using Spring Boot
22. Socket Programming In Java
25. Library Management System Project in Java
26. Trees in Java
28. Top Data Structures & Algorithms in Java
30. Top 55 Servlet Interview Questions
34. Java Collections Interview Questions and Answers
35. How to Handle Deadlock in Java?
36. Top 50 Java Collections Interview Questions You Need to Know
37. What is the concept of String Pool in Java?
38. What is the difference between C, C++, and Java?
39. Palindrome in Java- How to check a number or string?
40. Top MVC Interview Questions and Answers You Need to Know
41. Top 10 Applications of Java Programming Language
42. Deadlock in Java
43. Square and Square Root in Java
Originally published at https://www.edureka.co on August 20, 2019.
