Bright Java Tutorial

  package com.example.core;

  public class DecideByIfElse {

    public static void main(String[] args) {
      int intA = 1;
      int intB = 2;
	  //comparing int value using simple if statement
	  if(intA == 1) {
	    System.out.println("The value of intA is " 
	      + "equal to 1");
	  }
	  /*
	   * Since intA is equal to 1, all the lines of codes 
	   * inside the open and close curly brace will get 
	   * executed.
	   */
      //comparing int value using if and else statement
	  if(intB == 1) {
	    System.out.println("The value of intB is " 
	      + "equal to 1");
	  } else {
	    System.out.println("The value of intB is not " 
	      + "equal to 1");
	  }
	  /*
	   * Since intB is not equal to 1, all the lines of 
	   * codes inside the open and curly 
	   * brace for the else condition will get executed.
	   */
	  //comparing int value using if, else if, 
	  //and else statement
	  if(intA == intB) {
        System.out.println("The value of intA is equal to " 
          + "the value of intB.");
	  } else if(intA == 1) {
	    System.out.println("The value of intB is " 
	      + "equal to 1");
	  } else {
	    System.out.println("Nothing matched!");
	  }
	  /*
	   * The if statement will be first be evaluated. 
	   * In this case, it did not satisfy 
	   * the condition since intA is not equal to intB. 
	   * Then, the else if statement will be evaluated.
	   * This time, the condition is satisfied and all 
	   * the lines of codes inside the else if open and  
	   * close curly brace gets executed. The else  
	   * condition will no longer be evaluated since the 
	   * else if condition was already satisfied.
	   */
	  //The principles for all of the above examples can 
	  //be applied for other numeric data types
		
	  String stringA = "ABC";
	  String stringB = "abc";
	  //comparing String value using simple if statement
	  if(stringA.equals("ABC")) {
	    System.out.println("The value of stringA is ABC.");
	  }
	  /*
	   * To compare string values, we use the equals 
	   * String method. This comparison is case sensitive.
	   */
	  if(stringA.equals("ABC")) {
	    System.out.println("The value of stringA and " 
	      + "the value ABC are equal.");
	  }
	  //comparing string values in a non case sensitive way
	  if(stringA.equalsIgnoreCase(stringB)) {
	    System.out.println("The value of stringA and " 
	      + "stringB are equal without case sensitivity.");
	  }
	  //comparing using if and else statements
	  if(stringA.equals(stringB)) {
	    System.out.println("The value of stringA and " 
	      + "stringB are equal.");
	  } else if (stringA.equalsIgnoreCase(stringB)) {
	    System.out.println("The value of stringA and " 
	      + "stringB are equal without case sensitivity.");
	  }
	  /*
	   * As you may have guessed, the block of code under 
	   * the else if condition will get executed.
	   */
    }
  }
                           

  package com.example.core;

  /**
   * This will demonstrate how to control the
   * execution flow using the switch statement.
   * 
   * @author Rolan Liwanag
   *
   */
  public class DecideBySwitch {

	public static void main(String[] args) {
	  int varNum = 2;
	  //int and String are the common parameter passed
	  //in a switch statement
	  switch(varNum) {
	    case 1:
          System.out.println("1st place!");
          break;
        case 2:
          System.out.print("2nd");
          System.out.println(" place!");
          break;
        case 3:
          System.out.println("3rd place!");
        default:
          System.out.println("You lost!");
          break;
      }
	  /*
	   * We declared an int variable varNum with a 
	   * value of 2. We passed that value into the
	   * switch statement to be evaluated. It is 
	   * then evaluated if it is equal to 1. Since
	   * it evaluates to false, it is then evaluated
	   * if it is equal to 2. Since the test evaluates
	   * to true, then it executes the 1st print 
	   * command, then executes the second print
	   * command, then executes the break command.
	   * 
	   * NOTES: 
	   * 
	   * The break keyword is responsible for
	   * letting the program exit from the switch 
	   * statement. Without the break command, it
	   * will also execute the print commands from
	   * 'case 3' and 'default'.
       * 
	   * The 'default' will get executed in the
	   * above code if no 'case' condition is met.
	   */
	  String varStr = "abc";
      switch(varStr) {
        case "abb":
          System.out.println("It is abb");
          break;
        case "abc":
          System.out.println("It's abc");
          break;
        default:
          System.out.println("Default only");
          break;
      }
	  /*
	   * The above code shows how to evaluate a String
	   * variable in a switch statement.
	   */
	}
  }