What is Control Statement in Java – Definition | Syntax | Example
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Written By
The IoT Academy
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Published on
September 25th, 2023
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Updated on
January 22, 2024
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Making decisions in programming is similar to making decisions in everyday life. We face scenarios in programming when we need to execute a specific block of code. One of the necessities essential in Java programming is the use of control statements. A control statement in Java allows a program’s seamless flow.
Java’s control statements are crucial for programmers because they let them control how code executes. They can also define the conditions under which certain sections of a code should run. So, this blog is all about Java’s control statements, their types, and syntax with examples.
Control Flow Statements in Java
Every programmer knows about the statement, which is a way of telling the computer to do something. Java defines a control statement as a statement that decides whether or not to execute the other statements. Thus, it manages a program’s flow. In short, control structures in Java let you decide the way to carry out certain instructions.
A control statement acts as a determiner when deciding whether or not to execute the other statements’ next task. An “If” statement decides whether to execute a statement or which of the two statements should be executed first. Furthermore, there are three kinds of control statements in Java. They are selection statements, iteration statements, and jump statements.
Types of Control Statements in Java
Java has three types of control flow statements in Java:
- Decision Making
- Loop
- Jump
Let’s discuss each of them as well as the Java control statements program syntax.
1. Decision Making Statements
Decision-making statements choose which statement to execute and when. Therefore, depending on the outcome of the conditions you provide, these statements assess the Boolean expression and impact the program flow. In Java, there are two categories of decision-making statements.
The “if” statement in Java is a way to assess a condition. Thus, the control of the program changes depending on the specific condition. The If statement’s condition returns a Boolean value, either true or false. The four types of if-statements in Java are:
- Simple if statement
- if-else statement
- if-else-if ladder
- Nested if-statement
Syntax for if statement:
if(condition)
{
// Statements to execute if
// condition is true
}
This type of control statement in Java is almost identical to if-else-if statements. So, a single case from a collection of code blocks called cases in the switch statement executes depending on the variable you are switching. Additionally, it makes the program easier to read.
Syntax for switch statement:
switch (expression)
{
case value1:
statement1;
break;
case value2:
statement2;
break;
.
.
case valueN:
statementN;
break;
default:
statementDefault;
}
2. Loop Statements
Another useful type of control flow statement in Java is the Loop statement. In programming, it may be essential to regularly run a block of code while a certain condition is true. However, you may need to carry out the set of instructions repeatedly using loop statements. But, fulfilling a set of instructions depends upon certain conditions.
Three different loop types that operate similarly exist in Java:
After running the loop statements, the do-while loop verifies the condition at the end of the loop. Moreover, you can also use do-while loops when the number of iterations is unknown but you must run the loop at least once.
Syntax of the do-while loop:
do
{
//statements
} while (condition);
The while loop also serves to repeatedly loop through the amount of statements. However, it is best to use a while loop if you are unsure of the number of iterations.
Syntax of the while loop:
while(condition){
//looping statements
}
You can also call it enhanced for loop which offers an effective way for iterating across collections and arrays of data. Thus, the user doesn’t need to update the loop variable during this control statement in Java.
Syntax of the for-each:
for(data_type var : array_name/collection_name){
//statements
}
3. Jump Statements
Jump statements help to move program control to the targeted statements. Jump statements, then, pass execution control to the additional portion of the program. In Java control statements programs, jump statements come in two types, break statements and continue statements.
The break statement serves to break the program’s current flow. Moreover, it passes control to the following statement outside of a loop or switch statement. In the case of a nested loop, it just breaks the inner loop.
Syntax of the break statement in Java:
break;
The continue statement skips a certain section of the loop and instantly moves on to the next iteration. So, it is not like the break statement, which breaks the loop.
Syntax of the continue statement in Java:
continue;
Let’s understand the control statements in Java with a program or real example.
Control Statements Program in Java
public class Student {
public static void main(String[] args) {
int x = 20;
int y = 22;
if(x+y < 20) {
System.out.println(“x + y is less than 20”);
} else {
System.out.println(“x + y is greater than 20”);
}
}
}
Output: x + y is greater than 20
Tips to Use a Control Statement in Java
Keep the following best practices in mind when using control statements in Java:
- Use the control statement that is best suitable to the issue you want to solve.
- Aim for clearly defined and eventually false conditions in if statements and loops.
- Make sure your control statements are simple and easy to read, understand, and maintain.
- Avoid deep layering because less nesting helps maintain the readability of the code.
- Avoid infinite loops in a control statement in Java.
- To make your code easier to read, give your variables names that have meaning.
- Test your control statements using a variety of input scenarios to make sure they work as expected.
- Explain the logic underlying control statements in comments and documentation. Thus, it makes it easier to understand the logic in the future.
- Use Java nested control statements wisely as they can easily become confusing and complex.
Conclusion
A control statement in Java is a crucial component of programming and useful for managing a program’s execution path. Java has several control statements, each having advantages and disadvantages. Each of these Java control statements has a unique syntax and purpose. Moreover, you can use them to solve various programming issues.
Being a proficient Java programmer requires understanding the various control statements in the language. You must also know how to apply them efficiently. You may build effective, legible, and maintainable code by correctly using a control statement in Java.
Frequently Asked Questions
Q. What are control statements in OOP? Ans. Control statements are those that change the order of execution of statements.
Q. What is a control statement and loop? Ans. Loop control statements allow you to repeatedly execute a block of code.
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