String Functions(String handling commands

String functions or string handling commands allows us to examine and modify tring and convert tring to numeric values.

• The string function with a dollar sign($) at the end returns a string whereas a string function without a dollar sign returns a numeric value.
• String operation allow combination and comparison of strings.BASIC has the following string manipulation function.

LEFT$ function

The LEFT$ function returns a string that comprises the left most n characters of x$.

Syntax

LN LEFT$*(x$,n)

Where,

LN  : Line Number

x$   : string from which n left most characters are to be returned.

n     : number of characters

• The value of n must be within range of 0 to 255.
• if n = 0, the null tring (length zero) will be returned.

Example

10 LET P$ = "GOLDEN RING"

20 LET Q$ = LEFT$(P$,9)

The LEFT$ on line 20 will return nine characters of P$ string. o Q$ will have the string.

Q$= "GOLDEN RI"

Use the LEFT$ function in the program.

(1)CS 8.1 Dissplay on the screen for LEFT$ function 

Ok

LIST

10 REM use of LEFT$ function

20 P$ = "GOLDEN RING"

30 Q$ = LEFT$(P$,6)

40 print "Original String - "; P$

50 PRINT "Extracted String  - ";Q$

60 END

Ok

RUN

Original String - GOLDEN RING

Extracted String - GOLDEN

Ok

(2)CS Display on the screen for LEFT$ function

Ok

LIST

10   REM use of LEFT$ function

20   LET A$= " KATHMANDU"

30   FOR I = 1 TO 9

40   PRINT LEFT$ (A$,I)

50  NEXT I

60  END

Ok

RUN

K

KA

KATH

KATHM

KATHMA

KATHMAN

KATHMAND

KATHMANDU

Ok