Q(uick)BASIC Statement: MID$

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MID$

A string processing statement that replaces a portion of a string variable with another string

Worth knowing

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

Syntax

MID$(stringexpression$,start%[,length%])
MID$(stringvariable$,start%[,length%])=stringexpression$

Description/Parameter(s)

stringexpression$	The string from which the MID$ function returns a substring, or the replacement string used by the MID$ statement. It can be any string expression.
start%	The position of the first character in the substring being returned or replaced.
length%	The number of characters in the substring. If the length is omitted, MID$ returns or replaces all characters to the right of the start position.
stringvariable$	The string variable being modified by the MID$ statement.

Example

a$ = "Where is Paris?"
PRINT MID$(a$, 10, 5)       'Output is:  Paris
Text$ = "Paris, France"
PRINT Text$                 'Output is:  Paris, France
MID$(Text$, 8) = "Texas "
PRINT Text$                 'Output is:  Paris, Texas

Syntax

MID$(stringvariable,start[,length])=stringexpression

Description/Parameter(s)

Argument	Description
stringvariable	The string variable being modified.
start	A numeric expression giving the position in stringvariable where the replacement starts.
length	The length of the string being replaced. The length is a numeric expression.
stringexpression	The string expression that replaces part of the stringvariable.

The arguments start and length are integer expressions. The argument stringvariable is a string variable, but stringexpression can be a string variable, string constant, or string expression.

The optional length refers to the number of characters from the argument stringexpression that are used in the replacement. If length is omitted, all of stringexpression is used. However, regardless of whether length is omitted or included, the replacement of characters never goes beyond the original length of stringvariable.

Example

This example uses the MID$ statement to replace string characters.

CLS                        ' Clear screen
Test$ = "Paris, France"
PRINT Test$
MID$(Test$, 8)="Texas "    ' Starting at position 8, replace
                           ' characters in Test$ with Texas
PRINT Test$

Sample Output:

Paris, France Paris, Texas

Syntax

MID$(stringvariable$,start%[,length%])=stringexpression$

Description/Parameter(s)

stringvariable$	The string variable being modified.
start%	The character position at which the change starts.
length%	If included, the number of characters being replaced. The length% is a numeric expression.
stringexpression$	The new characters.

Usage Notes

The optional length refers to the number of characters from the argument stringexpression$ that are used in the replacement. If length% is omitted, all of stringexpression$ is used. However, regardless of whether length% is omitted or included, the replacement of characters never goes beyond the original length of stringvariable$.

Example

This example uses the MID$ statement to replace string characters.

CLS                        'Clear screen.
Test$ = "Paris, France"
PRINT Test$
MID$(Test$, 8) = "Texas "  'Starting at position 8, replace
                           'characters in Test$ with Texas.
PRINT Test$

Sample Output:

Paris, France Paris, Texas