Microsoft KB Archive/44799

= INSTR Function Performs ASCII Compare and Is Case Sensitive =

Article ID: 44799

Article Last Modified on 11/21/2006

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APPLIES TO


 * Microsoft QuickBasic Compiler for Macintosh 1.0
 * Microsoft BASIC Compiler 6.0b
 * Microsoft BASIC Interpreter 1.0
 * Microsoft BASIC Interpreter 1.01 for Macintosh
 * Microsoft BASIC Interpreter 2.0
 * Microsoft BASIC Interpreter 2.1 for Macintosh
 * Microsoft BASIC Interpreter 3.0 for Macintosh
 * Microsoft QuickBasic 1.0
 * Microsoft QuickBasic 1.01
 * Microsoft QuickBasic 1.02
 * Microsoft QuickBASIC 1.0b
 * Microsoft QuickBASIC 1.0b
 * Microsoft QuickBasic 2.0
 * Microsoft QuickBasic 2.01
 * Microsoft QuickBasic 3.0
 * Microsoft QuickBasic 4.0
 * Microsoft QuickBASIC 4.0b
 * Microsoft QuickBasic 4.5 for MS-DOS
 * Microsoft BASIC Compiler 6.0b
 * Microsoft BASIC Compiler 6.0
 * Microsoft BASIC Compiler 6.0b
 * Microsoft BASIC Professional Development System 7.0
 * Microsoft GW-BASIC Interpreter 1.0

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This article was previously published under Q44799



SUMMARY
The INSTR function (provided in all Microsoft BASICs) compares the ASCII values of the search string with the ASCII values of the string to be searched, and is, therefore, case sensitive. For example, when INSTR compares &quot;AB&quot; with &quot;Ab&quot;, INSTR returns 0 (zero) because the strings are different.

This information applies to the following products:


 * 1) Microsoft QuickBASIC Version 1.00 for the Apple Macintosh
 * 2) Microsoft BASIC Compiler Version 1.00 for the Apple Macintosh
 * 3) Microsoft BASIC Interpreter Versions 1.00, 1.01, 2.00, 2.10, and 3.00 for the Apple Macintosh
 * 4) Microsoft QuickBASIC Compiler Versions 1.00, 1.01, 1.02, 2.00, 2.01, 3.00, 4.00, 4.00b, and 4.50 for the IBM PC
 * 5) Microsoft BASIC Compiler Versions 5.35 and 5.36 for MS-DOS
 * 6) Microsoft BASIC Compiler Versions 6.00, and 6.00b for MS OS/2 and MS-DOS
 * 7) Microsoft BASIC Profesional Development System 7.00 for MS-DOS and MS OS/2
 * 8) Microsoft GW-BASIC Interpreter Versions 3.20, 3.22, and 3.23



MORE INFORMATION
The INSTR function returns the character position of the first occurrence of a string in another string. The syntax for INSTR is as follows

INSTR ( [Start,] string1, string2 )

where the variables refer to the following:   Variable  Description

Start    The [optional] character location to begin searching in             string1

string1  The character string to be searched

string2  The character string to be searched for The values returned by the INSTR function are as follows:   Value     Description

n        Refers to the character position of string2 in string1.

0        string2 was not found in string1.

0        string1 is a null string (&quot;&quot;).

0        The value for Start is greater than the length of string1. If string2 is a null string (&quot;&quot;), then INSTR returns the value of 1 unless a Start argument was specified, in which case it returns a value equal to Start.

For more information about the INSTR function, please consult your BASIC language reference manual.

Code Example
PRINT INSTR(&quot;ABCDEF&quot;,&quot;D&quot;)  ' Found in column 4. PRINT INSTR(&quot;ABCDEF&quot;,&quot;d&quot;)  ' Not found, since case differs Output:

4

0

Additional query words: QuickBas BasicCom MQuickB

Keywords: KB44799

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