WAP to convert binary number into decimal equivalent value

Qbasic program to convert binary number into decimal equivalent value

 CLS
 INPUT "ENTER BINARY NUMBER"; N$
 FOR I = LEN(N$) TO 1 STEP -1
 B$ = MID$(N$, I, 1)
 S = S + VAL(B$) * 2 ^ P
 P = P + 1
 NEXT I
 PRINT "DECIMAL EQUIVALENT VALUE="; S
 END

USING SUB

DECLARE SUB BDEC(N$)
 CLS
 INPUT "ENTER BINARY NUMBER"; N$
 CALL BDEC(N$)
 END
 
 SUB BDEC(N$)
 FOR I = LEN(N$) TO 1 STEP -1
 B$ = MID$(N$, I, 1)
 S = S + VAL(B$) * 2 ^ P
 P = P + 1
 NEXT I
 PRINT "DECIMAL EQUIVALENT VALUE="; S
 END SUB