If Statement
Description - If statement within block statement in 'then' part:
- Allowing the sequence of statements to be executed rather than just one.
Description: Nested if ... else statement
- The inner if statement will be executed firstly. - The else part always related to the closest if keyword
Description - if (Single-Selection) Statement:
- if keyword: started with the statement and followed by boolean expression. - Boolean expression, a == b,which must be in parantheses ( ) - If the value of boolean expression 'true', the then part is executed - If the value of boolean expression 'false', the then part is ignred and the statement following the if statement executed.
Description: if ... else (Double-selection) Statement
- if the boolean expression evaluated to true the statemet forming 'then' part is excuted. - Otherwise 'else' part will be excuted. - One and only one statement of 'then' and 'else' parts will be excuted.
Introduction
This Topic will Discuss: The if, if...else, and nested if statements Compound assignment, increment and decrements operators Portability of Java's primitive types
Example: if ... else (Double-selection) Statement
if (a == b) c = 10; // 'then' part else c = 20; // 'else' part h = 1.2 // Nest statement after the if
Example- if (Single-Selection) Statement:
if (a == b) c = 10; // the action statement after 'then' or body part h = 1.2; // next statement after the if. Not related to if.
Example: Nested if ... else statement
if (a == b) { If (c == d) { System.out.println ("c = d"); System.out.println ("a = b"); } else { System.out.println ("c != d"); System.out.println ("a != b"); } }
Example - If statement within block statement in 'then' part:
if (a == b) { c = 10; d = 20; f(); } h = 1.2; // next statement after the if. Not related to if.
Syntax - if ... else (Double-Selection) Statement:
if (boolean_expression) do_Something; else do_Otherthing;
Syntax - Nested if ... else Statement:
if (boolean_expression) do_Something1; else if (boolean_expression2) do_Something2; ..... else do_somthing_N;
Syntax - if (Single-Selection) Statement:
if (boolean_expression) do_something;
Objective:
• To provide binary selection, allowing conditional execution of a statement depending on the value of a boolean expression. • To choose among alternative actions.
