The Java compiler runs the code from beginning to end. The statements in the code are executed in the order that they occur in the code. Java, on the other hand, includes statements for controlling the flow of Java code. It is one of Java’s most important aspects, as it ensures a smooth program flow.

There are three different types of control flow statements in Java. They are as follows:

Decision-Making Statements:

As the name implies, decision-making assertions determine which and when to execute statements. Decision-making statements analyse the Boolean expression and control the program flow based on the condition’s result. In Java, there are two sorts of decision-making statements: If and switch statements.

If Statement: The “if” statement in Java is used to test a condition. Depending on the circumstances, the program’s control is diverted. The If statement’s condition returns a Boolean value, either true or false. There are four forms of if-statements in Java, as mentioned below.

Simple if: The most basic of all control flow statements in Java is simple if statements. It evaluates a Boolean statement and, if the expression is true, allows the program to begin a block of code. Syntax -

if-else: The if-else statement is an expansion of the if-statement that employs the else block of code. If the if-condition block is evaluated as false, the else block is executed. Syntax -

if-else-if ladder: The if-else-if statement is made up of an if statement and several else-if statements. In other words, a decision tree is created by a sequence of if-else statements in which the computer can enter the block of code where the condition is true. At the end of the chain, we may also define an else statement. Syntax -

Nested if-statement: The if statement can contain an if or if-else statement inside another if or else-if statement in nested if-statements. Syntax -

Switch Statement: Switch statements in Java are similar to if-else if-else statements. A single case is run based on the variable that is being switched in the switch statement, which comprises various blocks of code called cases. Instead of using if-else-if statements, you can use the switch statement. It also improves the program’s readability.

1. Integers, shorts, bytes, chars, and enumerations can all be used as case variables. Since Java version 7, the string type is also supported. Cases cannot be duplicated.


2. When any of the cases does not match the value of the expression, the default statement is executed. It’s a choice.


3. When the condition is met, the break statement ends the switch block.


4. If it is not utilised, the next case is executed.

We must remember that the case expression will be of the same type as the variable when employing switch statements. It will, however, be a constant value. Syntax -

Loop Statements:

In programming, we may need to run a piece of code multiple times while a condition evaluates to true. Loop statements are used to repeat the set of instructions. The execution of the set of instructions is contingent on a certain circumstance.

In Java, there are three different forms of loops that all work in the same way. However, there are differences in their syntax and the time it takes to check for conditions.

For Loop: The for loop in Java is comparable to the for loop in C and C++. In a single line of code, we may initialise the loop variable, check the condition, and increment/decrement. We only use the for loop when we know exactly how many times we want to run a block of code.

Syntax -

While Loop: The while loop can also be used to repeatedly iterate over a set of statements. If we don’t know the number of iterations ahead of time, though, we should use a while loop. In contrast to the for loop, the initialization and increment/decrement do not happen inside the while loop statement.

Because the condition is tested at the start of the loop, it’s also known as the entry-controlled loop. The loop body will be executed if the condition is true; else, the statements after the loop will be executed.

The while loop’s syntax is seen below.

Do While Loop: After running the loop statements, the do-while loop verifies the condition at the end of the loop. We can use a do-while loop when the number of iterations is unknown and we need to run the loop at least once.

Because the condition is not tested in advance, it is also known as the exit-controlled loop. The do-while loop’s syntax is seen below.

Jump Statements:

Jump statements are used to move the program’s control to certain statements. Jump statements, in other words, move the execution control to another area of the program. In Java, there are two types of jump statements: break and continue.

1. 
   break statement: The break statement, as its name implies, is used to interrupt the current flow of the program and pass control to the following statement outside of a loop or switch statement. In the event of a nested loop, however, it merely breaks the inner loop. In a Java program, the break statement cannot be used on its own; it must be inserted inside a loop or switch statement.


2. 
   continue statement: The continue statement, unlike the break statement, does not break the loop; instead, it skips the specific part of the loop and immediately moves to the next iteration of the loop.