Java if Statement

The condition in an if statement can be any expression that evaluates to a boolean value (true or false). This can include comparisons, such as x > y or x == y, or boolean operations, such as !flag (negation) or x && y (and). It is also possible to nest if statements, which allows you to test multiple conditions and execute different code blocks depending on the results.

Index

The if statement is a fundamental control structure in Java that allows you to execute a block of code if a certain condition is true. It is often used in conjunction with other control structures, such as for loops and while loops, to create more complex programs.

The syntax of the if statement is simple:

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

The condition can be any expression that evaluates to a boolean value (true or false). This can include comparisons, such as x > y or x == y, or boolean operations, such as !flag (negation) or x && y (and).

Here is an example of an if statement that checks if a number is positive:

int x = 10;
if (x > 0) {
  System.out.println("x is positive");
}

This code will output “x is positive” because the condition x > 0 is true.

It is also possible to nest if statements, which allows you to test multiple conditions and execute different code blocks depending on the results. For example:

int x = 10;
int y = 20;
if (x > 0) {
  if (y > 0) {
    System.out.println("both x and y are positive");
  } else {
    System.out.println("x is positive, y is not");
  }
} else {
  if (y > 0) {
    System.out.println("x is not positive, y is");
  } else {
    System.out.println("both x and y are not positive");
  }
}

This code will output “both x and y are positive” because both conditions x > 0 and y > 0 are true.

if Statement Example

Here is an example of an if statement in Java:

int x = 10;
if (x > 0) {
  System.out.println("x is positive");
}

This code will output “x is positive” because the condition x > 0 is true.

Here is another example that demonstrates how to use an if statement to check if a number is even or odd:

int x = 5;
if (x % 2 == 0) {
  System.out.println("x is even");
} else {
  System.out.println("x is odd");
}

This code will output “x is odd” because the condition x % 2 == 0 is false (the remainder of x divided by 2 is not equal to 0).

It is also possible to nest if statements, which allows you to test multiple conditions and execute different code blocks depending on the results. For example:

int x = 10;
int y = 20;
if (x > 0) {
  if (y > 0) {
    System.out.println("both x and y are positive");
  } else {
    System.out.println("x is positive, y is not");
  }
} else {
  if (y > 0) {
    System.out.println("x is not positive