LEN Function

LEN(string-expression)

Returns the length of a string in ASCII characters. The count includes all characters in the string, starting at 1 for the first character.

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Examples

PRINT LEN("Retro Rocket")

Produces 12.

REM Length of an empty string
PRINT LEN("")

Produces 0.

REM Use LEN to iterate over characters
name$ = "HELLO"
FOR i = 1 TO LEN(name$)
    PRINT MID$(name$, i - 1, 1)
NEXT

REM Truncate a string if too long
line$ = "This is a long string"
IF LEN(line$) > 10 THEN
    PRINT "Truncated: "; LEFT$(line$, 10)
ENDIF

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Notes

• Returns an integer value ≥ 0.
• Length is measured in characters, not bytes — since Retro Rocket BASIC strings are ASCII, the two are identical.
• Useful together with LEFT$, RIGHT$, and MID$ for string slicing.

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See also: LEFT$ · RIGHT$ · MID$ · ASC