Decision Making and Branching

Decision Making and Branching

üWhen a program breaks the sequential flow and jumps to another part of the code, it is known as branching. When branching is done on a condition it is known as conditional branching.

üThree decision making statements:

  1. if statement

  2. switch statement

  3. conditional operator statement

The if Statement

The if-else Statement

üAn else clause can be added to an if statement to make an if-else

 statement.

if ( condition )

   statement1;

else

   statement2;

Statement x;

üIf the condition is true, statement1 is executed;  if the 

condition is false, statement2 is executed.

üOne or the other will be executed, but not both.

Nested if….Else Statements

üThe if..else statement can be contained in another if or else statement.

  if (test condition1)

  { 

  if (test condition2)

  statement-1;

  else

  statement-2;

  }

  else

  statement-3;

 

  statement-x;

Nested if….Else Statements

üAn else clause is matched to the last unmatched if (no 

matter what the indentation implies!)

üExample:

  if(female)

  if(bal>5000)

  bon = 0.05 * bal;

  else

  bon = 0.02 * bal;

  bal = bal + bon;

üBraces can be used to specify the if statement to which an

 else clause belongs.

Multiway Selection: Else if

üSometime you want to select one option from several 

alternatives

if (conditon1)

    statement1;

else if (condition2)

    statement2;

else if (condition3)

    statement3;

else

    statement4;

Else if example

double numberGrade = 83.6;

char letterGrade;

if (numberGrade >= 89.5) {

    letterGrade = ‘A’;

} else if (numberGrade >= 79.5) {

    letterGrade = ‘B’;

} else if (numberGrade >= 69.5) {

    letterGrade = ‘C’;

} else if (numberGrade >= 59.5) {

    letterGrade = ‘D’;

} else {

    letterGrade = ‘F’;

}

System.out.println(“My Grade is ” + numberGrade + 

“, ” + letterGrade);

OUTPUT

My Grade is 83.6, B