Page 99 - Open Soource Technologies 304.indd

Unit 5: VB String and Operators

Objectives

After studying this unit, you will be able to:
• Understand string in visual basic
• Discuss operator and math operators
• Explain concatenation operators
• Understand logical operator
Introduction

A string is one or a combination of characters. To declare a variable for it, you can use either
the string or the Object data types. To initialize the variable, put its value in double-quotes and
assign it to the variable. Here are examples:
Public Module Exercise
Public Function Main( ) As Integer
Dim First Name As Object

Dim Last Name As String
First Name = “William”
Last Name = “Sansen”
Return 0
End Function

End Module
An Operator is a code element that performs an operation on one or more code elements that
hold values. Value elements include variables, constants, literals, properties, returns from Func-
tion and Operator procedures, and expressions.

5.1 Strings

The most common types of data processed by Visual Basic are numbers and strings. Sentences,
phrases, words, letters of the alphabet, names, telephone numbers, addresses, and Social Security
numbers are all examples of strings. Formally, a String literal is a sequence of characters that
is treated as a single item. String literals can be assigned to variables, displayed in text boxes
and list boxes, and combined by an operation called concatenation (denoted by &).

5.1.1 Variables and Strings
A String variable is a name used to refer to a String. The allowable names of String variables
are the same as those of numeric variables. The value of a String variable is assigned or altered
with assignment statements and displayed in a list box like the value of a numeric variable.
String variables are declared with statements of the form

LOVELY PROFESSIONAL UNIVERSITY 93