Control Statements in Java Programming Language

Control statements are used to control the flow of execution in a Java program. There are several types of control statements in Java including if, else if, nested if, and switch statements. In this explanation, we will go over each of these control statements and provide code examples with output.

Control Statements

If Statement

The if statement is used to execute a block of code only if a certain condition is true.

The syntax of the if statement is as follows:

if (condition) {
   // code to be executed if condition is true
}

Here’s an example of an if statement in Java:

int x = 5;

if (x > 0) {
    System.out.println("x is positive");
}

Output:

x is positive

Else If Statement in Java

The else if statement is used to execute a block of code if a certain condition is true and another condition is false. The syntax of the else if statement is as follows:

if (condition1) {
   // code to be executed if condition1 is true
} else if (condition2) {
   // code to be executed if condition2 is true
}

Here’s an example of an else-if statement in Java:

int x = 0;

if (x > 0) {
    System.out.println("x is positive");
} else if (x < 0) {
    System.out.println("x is negative");
} else {
    System.out.println("x is zero");
}

Output:

x is zero

Nested If Statement

A nested if statement is an if statement that is inside another if statement. This allows for more complex conditions to be checked. The syntax of a nested if statement is as follows:

if (condition1) {
   // code to be executed if condition1 is true
   
   if (condition2) {
      // code to be executed if condition1 and condition2 are true
   }
}

Here’s an example of a nested if statement in Java:

int x = 5;
int y = 10;

if (x > 0) {
    if (y > 0) {
        System.out.println("x and y are positive");
    }
}

Output:

x and y are positive

Switch Statement in Java

The switch statement is used to execute different actions based on different conditions. It is often used as a substitute for long if-else chains. The syntax of the switch statement is as follows:

switch (expression) {
   case value1:
      // code to be executed if expression is equal to value1
      break;
   case value2:
      // code to be executed if expression is equal to value2
      break;
   ...
   default:
      // code to be executed if expression is not equal to any of the values
}

Here’s an example of a switch statement in Java:

int day = 4;
String dayString;

switch (day) {
    case 1:
        dayString = "Monday";
        break;
    case 2:
        dayString = "Tuesday";
        break;
    case 3:
        dayString = "Wednesday";
        break;
    case 4:
        dayString = "Thursday";
        break;
    case 5:
        dayString = "Friday";
        break;
    case 6:
        dayString = "Saturday";
        break;
    case 7:
        dayString = "Sunday";
        break;
    default:
        dayString = "Invalid day";
        break;
}

System.out.println(dayString);

Output:

Thursday

Jumping Statements in Java

Continue Statement in Java

The continue statement is used inside loops to skip the current iteration and continue with the next iteration of the loop. The syntax of the continue statement is as follows:

continue;

Here’s an example of the continue statement in Java:

for (int i = 0; i < 10; i++) {
    if (i == 5) {
        continue;
    }
    System.out.print(i + " ");
}

Output:

0 1 2 3 4 6 7 8 9

In the example above, the continue statement is used inside a for loop to skip the iteration when the value of i is 5. The output shows that the value 5 is not printed, and the loop continues with the next iteration.

Break Statement in Java Programming

The break statement is used inside loops and switch statements to exit the loop or switch statements early. The syntax of the break statement is as follows:

break;

Here’s an example of the break statement in Java:

for (int i = 0; i < 10; i++) {
    if (i == 5) {
        break;
    }
    System.out.print(i + " ");
}

Output:

0 1 2 3 4

In the example above, the break statement is used inside a for loop to exit the loop when the value of i is 5. The output shows that the loop exits early and only prints values from 0 to 4.

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