Q(uick)BASIC Function: ASC

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ASC Function

A string processing function that returns a numeric value that is the ASCII code for the first character in a string expression

Worth knowing

Useful and cross-version information about the programming environments of QBasic and QuickBasic.

Syntax

ASC(stringexpression$)
CHR$(ascii-code%)

Description/Parameter(s)

stringexpression$	Any string expression.
ascii-code%	The ASCII code of the desired character.

ASC returns the ASCII code for the first character in a string expression.

CHR$ returns the character corresponding to a specified ASCII code.

Example

PRINT ASC("Q")    'Output is:  81
PRINT CHR$(65)    'Output is:  A

Syntax

ASC(stringexpression)

Description/Parameter(s)

If stringexpression is null, ASC produces a run-time error message "Illegal function call."

Example

The following example uses ASC to calculate a hash value - an index value for a table or file - from a string:

CONST HASHTABSIZE = 101
CLS                             'Clear the screen
INPUT "Enter a name: ",Nm$      'Prompt for input
TmpVal = 0
FOR I=1 TO LEN(Nm$)
    ' Convert the string to a number by summing the values
    ' of individual letters.
    TmpVal = TmpVal + ASC(MID$(Nm$,I,1))
NEXT I
    ' Divide the sum by the size of the table.
    HashValue = TmpVal MOD HASHTABSIZE
PRINT "The hash value is "; HashValue

Sample Output:

Enter a name: Bafflegab The hash value is 66

Syntax

ASC(stringexpression$)

Description/Parameter(s)

If the argument stringexpression$ is null, BASIC generates the run-time error message, "Illegal function call."

Example

This example uses the ASC function to calculate a hash value - an index value for a table or file - from a string.

CONST HASHTABSIZE = 101
CLS                             'Clear the screen.
INPUT "Enter a name: ", Nm$     'Prompt for input.
TmpVal = 0
FOR I = 1 TO LEN(Nm$)
    'Convert the string to a number by summing the values
    'of individual letters.
    TmpVal = TmpVal + ASC(MID$(Nm$, I, 1))
NEXT I
    'Divide the sum by the size of the table.
    HashValue = TmpVal MOD HASHTABSIZE
PRINT "The hash value is "; HashValue

Sample Output:

Enter a name: Bafflegab The hash value is 66