BASIC String Functions

LEFT$

TYPE: BASIC [String Function

FORMAT: LEFT$(string,integer)

Action: Returns a string comprised of the leftmost integer characters of the string. The integer argument value must be in the range 0 to 255. If the integer is greater than the length of the string, the entire string will be returned. If an integer value of zero is used, then a null string (of zero length) is returned.

Examples:

  10 A$ = "AQUARIUS COMPUTERS"
  20 B$ = LEFT$(A$,8): PRINT B$
  RUN

Prints AQUARIUS

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MID$

TYPE: BASIC [String Function

FORMAT: MID$(string,numeric-1[,numeric-2])

Action:

The MID$ function returns a sub-string which is taken from within a larger string argument. The starting position of the sub-string is defined by the numeric-1 argument and the length of the sub-string by the numeric-2 argument. Both of the numeric arguments can have values ranging from 0 to 255.

If the numeric-1 value is greater than the length of the string, or if the numeric-2 value is zero, then MID$ gives a null string value. If the numeric-2 argument is left out, then the BASIC will assume that a length of the rest of the string is to be used. If the source string has fewer characters than numeric-2, from the starting position to the end of the string argument, then the whole rest of the string is used.

Examples:

10 A$="GOOD"
20 B$="MORNING EVENING AFTERNOON"
30 PRINT A$ + MID$(B$,8,8)

Prints GOOD EVENING

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RIGHT$

TYPE: BASIC [String Function

FORMAT: RIGHT$ ( string , length )

Action: Returns a sub-string taken from the right-most end of the string argument. The length of the sub-string is defined by the numeric argument which can be any integer in the range of 0 to 255. If the value of the numeric expression is zero, then a null string ("") is returned. If the value you give in the numeric argument is greater than the length of the string then the entire string is returned.

Examples:

10 MSG$="Aquarius+ Computer"
20 PRINT RIGHT$(MSG$,8)
RUN

Prints Computer

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PAD$

TYPE: plusBASIC v0.22t string function

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FORMAT: PAD$( expression , length )

Action: Returns a string contain string padded with spaces to length length.

• expression is the string to be padded.
  • If expression is numeric, it is automatically converted to a string.
• length is an expression that evaluates to an integer in the range -255 through 255.
• If length is positive, spaces are added to the left.
  • If string is longer than length, the first length characters are returned.
• If length is negative, spaces are added to the left.
  • If string is longer than length, the last length characters are returned.
• If length is 0, an empty string is returned.

Examples:

PAD$("xyz",9) 

Returns "xyz "

PAD$(123,9) 

Returns "123 "

PAD$("xyz",-10)

Returns " xyz"

PAD$("234",-6)

Returns " 234"

PAD$("xyz",1)

Returns "x"

PAD$("xyz",-2)

Returns "yz"

PAD$("xyz",0)

Returns ""

FORMAT: PAD$( expression , length , char )

Action: As above, but the string is padded with char instead of spaces.

• char is an expression that evaluates to either a string or an integer in the range 0 through 255.
  • If char is an integer, the string is padded with the corresponding ASCII character.
  • If char is a string, the first character is used as the pad character.
  • Illegal quantity results if char is an empty string.

Examples:

PAD$("xyz",9,"!")

Returns "xyz!!!!!!"

PAD$(123,9,"x")

Returns "123!!!!!!"

PAD$("xyz",-10,"@")

Returns "@@@@@@@xyz"

PAD$(456",-6,"0")

Returns "000456"

PAD$("xyz",5,0)

Returns "xyz££"

PAD$("xyz",-6,0)

Returns "£££xyz"

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TRIM$

TYPE: plusBASIC v0.21x [String Function

FORMAT: TRIM$ ( string )

Action: Trims white space characters from both ends of string.

• string is the string to be trimmed.
• Whitespace characters are characters with an ASCII value less than or equal to 32 (Space).

Examples:

TRIM$("   123   ")

Returns string 123

TRIM$("      ")

Returns string with length 0.

FORMAT: TRIM$(string,chars)

Action: As above, but trims the specified characters from each end of the string.

• chars is a string containing a list of characters to be trimmed.

Examples:

TRIM$("@@@123@@@","@") 

Returns string 123.

TRIM$("@@@@@@","@") 

Returns string with length 0.

TRIM$("#*#abc#*#","*#")

Returns string abc.

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TRIML$

TYPE: plusBASIC v0.21x [String Function

FORMAT: TRIML$ ( string )

Action: As above but trims whitespace characters from the left end of the string.

Examples:

PRINT TRIML$("   123   ");"x" `

Returns string 123 .

TRIML$("      ")

Returns string with length 0.

FORMAT: TRIML$(string,chars)

Action: As above, but trims the specified characters from the left end of the string.

Examples:

TRIML$("@@@123@@@","@") 

Returns string 123@@@.

TRIML$("@@@@@@","@")

Returns string with length 0.

TRIML$("#*#abc#*#","*#")

Returns string abc#*#.

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TRIMR$

TYPE: plusBASIC v0.21x [String Function

FORMAT: TRIMR$ ( string )

Action: As above but trims whitespace characters from the left end of the string.

Examples:

TRIMR$("   123   ")

Returns string 123.

TRIMR$("      ")

Returns string with length 0.

FORMAT: TRIMR$(string,chars)

Action: As above, but trims the specified characters from the left end of the string.

Examples:

 TRIMR$("@@@123@@@","@")

Returns string @@@123.

TRIMR$("@@@@@@","@")

Returns string with length 0.

`'' TRIMR$("##abc##","*#") '''

Returns string #*#abc.

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STRING$

TYPE: plusBASIC string function

FORMAT: STRING$ ( length )

Action: Returns a string of composed of length spaces (ASCII code 32).

• _length _ is an expression that evaluates to an integer.
• Illegal Quantity Error results if length is not in the range 0 through 255.

Examples:

PRINT "<";STRING$(20);">"

Prints < >

FORMAT: STRING$ ( length , byte )

Action: As above, but the string is composed of the characters with ASCII code byte.

• _byte _ is an expression that evaluates to an integer.
• Illegal Quantity Error results if byte is not in the range 0 through 255.

Examples:

PRINT STRING$(5,64)

Prints @@@@@

PRINT STRING$(3,'Z')

Prints ZZZ

FORMAT: STRING$ ( length , string )

Action: As above, but the string is composed of the first character of string.

• Illegal Quantity Error results if string is empty.

Examples:

  10 X$=STRING$(10,"-")
  20 PRINT X$;"MONTHLY REPORT";X$

Prints ----------MONTHLY REPORT----------