CVI

• Source: https://www.freebasic.net/wiki/wikka.php?wakka=KeyPgCvi
• Last revised: 2017-07-01

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Converts a floating-point number or string to an integer variable using a binary copy

Syntax

32-bit:
declare function Cvi ( byval f as single ) as integer
64-bit:
declare function Cvi ( byval f as double ) as integer

declare function Cvi ( byref str as const string ) as integer
declare function Cvi`<bits>` ( expr as DataType ) as integer`<bits>`

Usage

result = Cvi( sng )
result = Cvi( str )
result = Cvi<bits>( expr )

Parameters

f

A floating-point number with a binary copy of an integer variable stored in it. Its precision (Single or Double) depends on the size of Integer on the current platform

str

A String with a binary copy of an integer variable stored in it.

bits

Specifies a size of integer type to return. The types and sizes of expr accepted will depend on the corresponding function called.

expr

An expression that will be copied into an Integer<bits>.

Return Value

An Integer or Integer<bits> variable containing a binary copy of the input expression.

Description

Returns an integer value using the binary data contained in a floating-point value, or a String. A value of zero (0) is returned if the string contains fewer characters than the size of the return type.

Cvi can be used to convert strings created with Mki.

This function can also be used to convert Integer-sized values from a memory or file buffer without the need for a Type structure. However, just as with the type structure, special care should be taken when using Cvi to convert strings that have been read from a buffer.

Cvi supports an optional <bits> parameter before the argument. If bits is 16, Cvshort will be called instead; if bits is 32, Cvl will be called; if bits is 64, Cvlongint will be called. The return type and accepted argument types will depend on which function is called. See each function's page for more information.

Cvi's behaviour changes depending on the size of the Integer data type on the current platform.

• For 16-bit Integer (-lang qb), a 16-bit value is returned, and no floating-point types are accepted.
• For 32-bit Integer, a 32-bit value is returned, and numeric arguments are interpreted as Single precision values.
• For 64-bit Integer, a 64-bit value is returned, and numeric arguments are interpreted as Double precision values.

Examples

start GeSHi

Dim i As Integer, s As String
s = "ABCD"
i = CVI(s)
Print Using "s = ""&"""; s
Print Using "i = _&H&"; Hex(i)

end GeSHi

Dialect Differences

• In the -lang qb dialect, Cvi expects a 2-byte string, since a QB integer is only 16 bits. Only the first two bytes of the string are used, even if the string happens to be longer than two bytes.
• In the -lang qb dialect, Cvi will not take a floating-point argument, since a QB integer is only 16 bits and there is no 16-bit floating-point data type. Instead, Cvi<32>/Cvi<64> or Cvl/Cvlongint may be used.

Differences from QB

• In QB an error occurs if the string passed is fewer than two bytes in length.
• QB did not support floating-point arguments.
• QB did not support a <bits> parameter.

See also

• Mki
• Cvshort
• Cvl
• Cvlongint
• Integer

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