JAVA-Flow Control Statements - Notes By ShariqSP

Flow Control Statements in Java

In Java, flow control statements are used to control the order of execution of statements in a program. They allow you to make decisions, repeat statements, and branch based on conditions.

Simple If Statement

The simple if statement is used to execute a block of code only if the condition specified is true.

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

If-else Statement

The if-else statement is used to execute one block of code if the condition is true and another block of code if the condition is false.

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

If-else-if Statement

The if-else-if statement is used to test multiple conditions. It executes different blocks of code depending on the true condition.

                  if (condition1) {
                      // code to be executed if condition1 is true
                  } else if (condition2) {
                      // code to be executed if condition2 is true
                  } else {
                      // code to be executed if all conditions are false
                  }
                

Switch Statement

The switch statement allows you to select one of many code blocks to be executed based on the value of an expression.

                  switch (expression) {
                      case value1:
                          // code to be executed if expression equals value1
                          break;
                      case value2:
                          // code to be executed if expression equals value2
                          break;
                      default:
                          // code to be executed if expression doesn't match any case
                  }
                

Looping Statements in Java

Looping statements in Java are used to execute a block of code repeatedly based on a condition.

For Loop

The for loop executes a block of code a specified number of times.

                  for (initialization; condition; update) {
                      // code to be executed
                  }
                

Example:

                  for (int i = 0; i < 5; i++) {
                      System.out.println(i);
                  }
                

While Loop

The while loop executes a block of code as long as the specified condition is true.

                  while (condition) {
                      // code to be executed
                  }
                

Example:

                  int i = 0;
                  while (i < 5) {
                      System.out.println(i);
                      i++;
                  }
                

Do-While Loop

The do-while loop is similar to the while loop, but the condition is evaluated after the execution of the block.

                  do {
                      // code to be executed
                  } while (condition);
                

Example:

                  int i = 0;
                  do {
                      System.out.println(i);
                      i++;
                  } while (i < 5);
                

For-Each Loop

The for-each loop is used to iterate over elements in an array or a collection.

                  for (type variable : array/collection) {
                      // code to be executed
                  }
                

Example:

                  int[] numbers = {1, 2, 3, 4, 5};
                  for (int num : numbers) {
                      System.out.println(num);
                  }