Blog_Banner_Asset
    Homebreadcumb forward arrow iconBlogbreadcumb forward arrow iconFull Stack Developmentbreadcumb forward arrow iconControl Statements in Java: What Do You Need to Know in 2024

Control Statements in Java: What Do You Need to Know in 2024

Last updated:
3rd Oct, 2022
Views
Read Time
10 Mins
share image icon
In this article
Chevron in toc
View All
Control Statements in Java: What Do You Need to Know in 2024

What is Control Statement?

Control Statements interpolates the concept of modifying the flow of your code. When it comes to coding, you have to understand that the computer runs through your code in a specific way and executes most of the code from top to bottom. It goes to the first line, then to the second line, and so on till it reaches the bottom of the code from left to right.

This means that it fetches the value on the right-hand side and assigns into the left-hand side of the variable, as a general rule, but every rule has an exception which introduces the Control Structures or statements.

If you want to modify the sequential execution of the code flow, you have to do a transfer of control or use the control structure. A control statement determines whether the next set of tasks have to be executed or not.

Let us explain the control structure with a simple example using an “if” statement, a type of decision-making control statement. Java is a case sensitive language, which implies that the case structure has to be specific. IF cannot be capitalized, let us write something inside the if statement to determine whether or not a particular thing is true or false.

Ads of upGrad blog

Check out our free courses to get an edge over the competition

In this case, declare a variable called “name,” assign a value to that “name,” and check the value of the name. If the value is not equal to null, then action must be performed, like a print out the title to the Java console or output the value inside the variable called “name.” This helps to know what is going on in the application in real-time.

We evaluate an expression inside a control structure and determine whether the condition is true or false. If the expression evaluates to the wrong inside a control structure, it skips everything inside the scope of that particular control structure, skips the line of code, and goes outside and ends the program.

Check out upGrad’s Advanced Certification in Cloud Computing

Read: Java Interview Questions & Answers

Control Structures or Statements in Java

The following are the Control structures that can be applied to any computer program. Control Statements are the essential structuring elements for the flow of program execution. They can branch, break, or advance program execution flow based on the change in program states.

Check out upGrad’s Advanced Certification in Blockchain

Sequence Structure

This structure refers to the sequential execution of statements one after the other, as specified in the code. This is the default structure built into Java wherein the statements are executed one after the other from beginning to end unless instructed otherwise.

Selection Structure

This structure will let us choose a path based on a given condition. Java has three types of Selection statements, namely, if statement, if-else-statement, and switch statement. Selection statements are also called as decision-making statements. If and switch statements allow you to control the program execution flow based on the condition at runtime.

If Statement

This statement allows the program to start, reach a decision based on the set condition. This means a code can or cannot be executed.

Example:

If (x<20) {

System.out.printIn(“Hello Universe!”);

}

If-else-else Statement

The program starts and reads the decision based on the set condition and continues to do one thing or another and concludes.

Example:

If (x<20) {

System.out.printIn(“Hello Universe!”);

}

Else {

System.out.printIn(“Hello folks!”);

}

Explore our Popular Software Engineering Courses

Switch or break Statement

The program starts, reach decisions to be made. A variable is compared to different values, and depending on the variable cost, a certain path of execution is chosen. Hence, other choices are available for the program to conclude.

Example:

switch (dayNumber) {

Case 1:

dayName = “Monday”;

break;

Case 2:

dayName = “Tuesday”;

break;

Case 3:

dayName = “Wednesday”;

break;

default:

dayName = “Any other Day”;

break;

}

Must Read: Pattern Programs in Java

upGrad’s Exclusive Software Development Webinar for you –

SAAS Business – What is So Different?

 

Repetition Structure

Repetition structure allows us to execute code statements repetitively or zero times, depending on the condition.

We have three types of repetition/ looping statements/iteration in Java, namely, for a statement, while information, and do while statement. Iteration statements enable program execution to repeat one or more statements, such as a loop, for a loop. Each loop has four types of statements, namely,

  • Initialization
  • Condition Checking
  • Execution
  • Increment/Decrement

For Loop

This statement is used when the number of iterations is known before entering the loop. This loop is used to evaluate the initial value statements to the final value with a given increment/decrement.

Example:

for(m=1;m<=20;m=m+1)

{

  System.out.println(m);

}

classfor1

{

  public static void main(String args[])

{

int i;

for (i=0;i<5;i++)

{ 

      System.out.println(“\nExample of for loop”);

  }

}

Output:

Example of for loop

Example of for loop

Example of for loop

Example of for loop

Example of for loop

 

Example:

for(int i=20; i>1; i–) {

System.out.printIn(“The value of i is: ” + i);

}

The control variable is initialized and repeated as long as the condition is true, and when the condition is false, the program ends.

While Loop

This loop is used to evaluate the statements from the initial value to the final value with a given increment/decrement.

loop.

m=1

while(m<=20)

{

 System.out.printIn(m);

 m=m+1;

}

Example

print values from 1 to 10

Class while1

{

  public static void main(String aargs[])

  {

inti=1;

while(i<=10)

{

      System.out.printIn(“\n” + i);

   i++;

}

  }

}

Output:

1

2

3

4

5

6

7

8

9

10

do while loop

This loop is used to evaluate the statements from initial value to final value with given increment/decrement

m=1

do

{

System.out.printIn(m);

m=m+1;

}

while(m==20);

 

class dowhile1

{

  public static void main(String args[])

  {

int i = 1;

int sum = 0;

do

{

    sum = sum + i;

    i++;

}while (i<=10);

    System.out.printIn(‘\n\n\iThe sum of1to 10 is..” + sum);

  }

}

Output:

The sum of 1 to 10 is ..55

One of the major differences between the while loop and the do-while loop is that in a do-while loop, you will be executing the body of the loop initially and then check the condition. the do-while loop executes the block of the statement even when the condition fails, and it executes one time.

In-Demand Software Development Skills

Branching Statements

Break, continue, and Return fall under the Branching Statements.

When we are working with looping statement, it is sometimes desirable to escape some statements inside the loop or terminate the loop immediately without checking the test expression. In that case, break and continue statements are used. These are the keywords that should be returned, followed by a semicolon. The break statement causes an immediate exit from loops or switch blocks for the execution of break statements. The control moves to this statement just after the loop objects which block or body of the loop. The break statement will break the loop and terminate it from the loop. The continue statement escapes the rest of the current iteration and proceeds with the loop’s next iteration. In the case of do-while, the control of the program moves to the test expression for further iteration. In the case of a loop, the control moves to the update expression.

Break Statement

Break statement has two forms, namely labeled and unlabeled. Break-in unlabeled switch statements can also be used to terminate the while do-while loop. Let us explain with an example.

Java switch statement is like an if-else statement that executes one of the conditions based on the switch input. In general, after the case is evaluated, even after the first match is met unless break is used inside the case to exit, the switch new possible values are listed using the case labels. These labels in Java may contain only constants. Execution will start after the layer. An optional default label may also be present to declare that the code will be executed. 

We are sending an argument, passing it to an integer, namely marks, and the marks variable goes to switch as a parameter. If the marks are 95, it will print this message “your marks on the rank” without a break. It continues to the next case and to the default case that is executed when the above cases are not met.

Example:

public class BreakDemo {

public static void main(string[] args) {

String str1 = args[0];

int marks = Integer.parselnt(str1);

switch(marks){

 case 95: System.out.println(“Your marks: “+marks” and rank is A”);

   break;

 case 80: System.out.println(“Your marks: “+marks” and rank is B”);

   break;

 case 70: System.out.println(“Your marks: “+marks” and rank is c”);

   break;

 default:

System.out.println(“Your marks: “+marks” and rank is FAIL”);

   break;

  }

 }

 }

Continue Statement

This example is to print odd numbers. The continue statement skips the iteration of for, while loops.

Example:

Continue-demo

public class ContinueDemo {

public static void main(string[] args) {

   for(int i=1;i<=10;i++){

   if(i%2 == 0) continue;

   System.out.println(“Odd number ” + i);

   }

  }

  }

Get Software Development Course from the World’s top Universities. Earn Executive PG Programs, Advanced Certificate Programs, or Masters Programs to fast-track your career.

Explore Our Software Development Free Courses

Return Statement

The return statement is used to return the value from a method explicitly. The called class will process and transfer the control back to the caller of the method. The data type of the return value must match the type of methods declared return value. If a method is declared as void, it does not return a value.

Example:

Class Rectangle {

 int length;

 int breadth;

Void setDim(int le, int br){

 length = le;

 breadth = br;

 }

 int getArea() {

 return length * breadth;

 }

}

Connecting the Control Structure and connect the statements control structures in two ways, one is by stacking, and the other is by nesting.

Control Statement Stacking

Ads of upGrad blog

The entry point of one activity diagram can be connected to the exit point of another. For example, a sequence statement and a selection statement can be combined through stacking.

Control Statement Nesting

An instruction or action in one control statement is replaced with another control statement. 

Also Read: Java Project Ideas & Topics

What Next?

If you’re interested to learn more about Java, full-stack software development, check out upGrad & IIIT-B’s Executive PG Program in Full-stack Software Development which is designed for working professionals and offers 500+ hours of rigorous training, 9+ projects, and assignments, IIIT-B Alumni status, practical hands-on capstone projects & job assistance with top firms.

Profile

Rohan Vats

Blog Author
Software Engineering Manager @ upGrad. Passionate about building large scale web apps with delightful experiences. In pursuit of transforming engineers into leaders.

Frequently Asked Questions (FAQs)

1What are the features of the Java programming language?

The Java Programming Language has a lot of features. To begin with, it is a language of programming that is regarded to be simple to learn. Java is an object-oriented programming language with simple functions, keywords, and variables. This makes it simple to understand for novices. Furthermore, Java comes with a built-in security feature that aids in the development of a virus-free and tamper-proof system for users. This avoids data tampering and confidential code hacking. Everything in Java is considered an object, according to OOP. Finally, Java is not compiled into a machine that is specialized in a particular platform. Instead, it is compiled into bytecode that is platform-agnostic. This code is processed by the Virtual Machine, which allows the platform to execute from any location and any device.

2What are the real-life use cases of Java?

Java is not only used in a variety of devices, such as desktop computers and mobile phones but is also used to create websites and applications. Java is utilized to address the technological demands of a wide range of industries and enterprises. It is used to process transactions in the financial business, for example. The IT sector employs most Java developers since it is engaged in information technology to facilitate operational needs. Companies use it in the stock market because algorithms assist them in determining which stocks to invest in. As a result, Java isn't limited to a particular application and is used by many prominent organizations.

3What is the scope of Java developers?

Java developers have a promising future in all industries. Despite its origins in C and C++, it is an object-oriented programming language with a simplified object model. It provides the JVM, a virtual computer that is loaded with bytecode and may operate on any system. Consequently, establishing a career in Java is both wise and financially rewarding. Because of its vibrant community, enterprise support, and rising popularity among programmers, Java is anticipated to remain the primary option for most businesses. As a result, Java career opportunities aren't likely to fade away any time soon.

Explore Free Courses

Suggested Blogs

Top 7 Node js Project Ideas &#038; Topics
31373
Node.JS is a part of the famous MEAN stack used for web development purposes. An open-sourced server environment, Node is written on JavaScript and he
Read More

by Rohan Vats

05 Mar 2024

How to Rename Column Name in SQL
46787
Introduction We are surrounded by Data. We used to store information on paper in enormous file organizers. But eventually, we have come to store it o
Read More

by Rohan Vats

04 Mar 2024

Android Developer Salary in India in 2024 [For Freshers &#038; Experienced]
901147
Wondering what is the range of Android Developer Salary in India? Software engineering is one of the most sought after courses in India. It is a reno
Read More

by Rohan Vats

04 Mar 2024

7 Top Django Projects on Github [For Beginners &amp; Experienced]
51372
One of the best ways to learn a skill is to use it, and what better way to do this than to work on projects? So in this article, we’re sharing t
Read More

by Rohan Vats

04 Mar 2024

Salesforce Developer Salary in India in 2024 [For Freshers &#038; Experienced]
908711
Wondering what is the range of salesforce salary in India? Businesses thrive because of customers. It does not matter whether the operations are B2B
Read More

by Rohan Vats

04 Mar 2024

15 Must-Know Spring MVC Interview Questions
34595
Spring has become one of the most used Java frameworks for the development of web-applications. All the new Java applications are by default using Spr
Read More

by Arjun Mathur

04 Mar 2024

Front End Developer Salary in India in 2023 [For Freshers &#038; Experienced]
902278
Wondering what is the range of front end developer salary in India? Do you know what front end developers do and the salary they earn? Do you know wh
Read More

by Rohan Vats

04 Mar 2024

Method Overloading in Java [With Examples]
25887
Java is a versatile language that follows the concepts of Object-Oriented Programming. Many features of object-oriented programming make the code modu
Read More

by Rohan Vats

27 Feb 2024

50 Most Asked Javascript Interview Questions &#038; Answers [2024]
4032
Javascript Interview Question and Answers In this article, we have compiled the most frequently asked JavaScript Interview Questions. These questions
Read More

by Kechit Goyal

26 Feb 2024

Schedule 1:1 free counsellingTalk to Career Expert
icon
footer sticky close icon