Programming Visual Basic .NET

Literals

Literals are representations of values within the text of a program. For example, in the following line of code, 10 is a literal, but x and y are not:

x = y * 10

Literals have data types just as variables do. The 10 in this code fragment is interpreted by the compiler as type Integer because it is an integer that falls within the range of the Integer type.

Numeric Literals

Any integer literal that is within the range of the Integer type (-2147483648 through 2147483647) is interpreted as type Integer, even if the value is small enough to be interpreted as type Byte or Short. Integer literals that are outside the Integer range but are within the range of the Long type (-9223372036854775808 through 9223372036854775807) are interpreted as type Long. Integer literals outside the Long range cause a compile-time error.

Numeric literals can also be of one of the floating point types—Single, Double, and Decimal. For example, in this line of code, 3.14 is a literal of type Double:

z = y * 3.14

In the absence of an explicit indication of type (discussed shortly), Visual Basic .NET interprets floating point literals as type Double. If the literal is outside the range of the Double type (-1.7976931348623157E308 through 1.7976931348623157E308), a compile-time error occurs.

Visual Basic .NET allows programmers to explicitly specify the types of literals. Table 2-2 (shown later in this chapter) lists Visual Basic .NET’s intrinsic data types, along with the method for explicitly defining ...