VAL

The VAL function returns the decimal numerical equivalent value of a STRING numerical value.

Syntax

numericValue = VAL(stringValue$[, numericalType])

Parameters

• stringValue$ is a STRING containing a sequence of digit characters which shall be converted into a numeric value.
  • May also contain the letters E, D and F for an exponent value in the scientific notation.
  • The number as well as a given exponent value may be prepended with a plus(+) or minus(-) sign and any spaces in between the characters are ignored.
  • The string may also start with &B, &H or &O to denote a binary, hexadecimal or octal number string respectively. However, only leading spaces (before the & character) are ignored here.
• numericalType is optional and specifies the target type for the conversion. Accepted types are:
  • SINGLE
  • DOUBLE
  • _FLOAT
  • _BYTE
  • INTEGER
  • LONG
  • _INTEGER64
  • _OFFSET
• The _UNSIGNED modifier is also allowed and can be combined with the integer types.

Description

• The regular (decimal) conversion stops at non-numeric characters except for spaces and the letters E, D and F for specifying an exponent. But note, the string cannot be an exponent only, i.e. if the first non-space and non-sign string character is not a digit, then VAL returns zero(0). Same happens if it is a sign or spaces only.
• For binary, hexadecimal or octal strings conversion stops at digits or letters which are invalid in the respective number base system.
• Note that this function cannot be used to return the ASCII value of a string character, use the ASC (function) for that purpose.

Availability

• 
  all
• 
  all
• 
• 
  yes
• 
  yes
• 
  yes

• In QB64-PE v4.2.0 support for numericalType was added.

Examples

Example 1

Differences in values returned with QBasic and QB64(PE).

PRINT VAL("&H") '203 in QB, 0 in QB64 PRINT VAL("&HFFFF") ' -1 QB, 65535 in QB64 PRINT VAL("&HFFFF&") '65535 in both

Explanation A quirk in QBasic returned VAL values of 203 for & and &H that was never fixed until PDS(7.1).

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Example 2

Converting a string with some number characters in it.

text$ = "1.23Hello" number! = VAL(text$) PRINT number!

1.23

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Example 3

Converting a literal and a variable string to numerical values and add them.

a$ = "33" PRINT VAL("10") + VAL(a$) + 1

44

Explanation You have to convert the string to values in order to use them in a mathematical expression. If VAL wasn't used here, then the program would break with an error, as you can't add strings and numbers.

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Example 4

Converting a hexadecimal value to decimal value using HEX$ with VAL.

decnumber% = 96 hexnumber$ = "&H" + HEX$(decnumber%) 'convert decimal value to hex and add hex prefix PRINT hexnumber$ decimal% = VAL(hexnumber$) PRINT decimal%

&H60 96

Explanation HEX$ converts a decimal number to hexadecimal, but VAL will only recognize it as a valid value with the &H prefix.

See also

• ASC (function), STR$
• _BIN$, HEX$, OCT$

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