Java An Introduction to Problem Solving and Programming Chapter 4.1 (Notes)

Java Loop Statements

• A loop repeats a group of statements.

• Java has several statements for controlling loops.

The while Statement

• A while loop repeats its body while a boolean expression is true.

• The body of a while loop often is a compound statement.

• Do not write a semicolon after the beginning of a while statement.

• while(boolean_expression){

First_Statement

Second_Statement

....

Last_Statement

}

The do-while Statement

• A do-while loops also repeats its body while a boolean expression is true.

• The body of a do-while loop often is compound statement.

• A do-while loop repeats its body at least once.

• do{

First_Statement

Second_Statement

....

Last_Statement

}while(boolean_expression);

Infinite Loops

• An infinite loop executes repeatedly due to an error in logic.

• Learn how to force a program to stop running.

Nested Loops

• The body of one loop can contain another loop.

The for Statement

• A for statement groups the major aspects of a loop.

• A for loop is logically equivalent to a while loop.

• Do not write a semicolon after the beginning of a for statement.

Declaring Variables Within a for Statement

• A variable's scope is where it has meaning in a program.

Using a Comma in a for Statement (Optional)

• A comma can separate multiple initializations in a for statement.

The for-each Statement

• A for-each statement iterates for each item in a data collection.