CIS 3020 Part 4

Variables

Variable: An identifier that can be given a value

• Associated with primitive types

Reference Variable: A variable whose value is a reference

• Associated with instances of a class
• Most programmers refer to both as variables
• There is a fundamental difference in how they are used internally

String Methods

Method	Return Value	Arguments	Definition
toUpperCase	Reference to String Object	None	Shifts all alpha-characters to uppercase
toLowerCase	Reference to String Object	None	Shifts all alpha-characters to lowercase
length	int	None	Returns number of characters in string
trim	Reference to String Object	None	Removes white space from end of string object
concat	Reference to String Object	Reference to String Object	Concatenates string object in argument to original string object
substring	Reference to String Object	int	Returns substring of original string from position given to end
substring	Reference to String Object	int,int	Returns substring of original string from position given to second position given

Bound Variables

Given two methods:

public int test (int x) { body1 }

public int square (int x) { body2 }

are the two x's the same?

No! These are formal parameters of their respective methods. The method definitions bind them.