Source code of 6.1.5 - Sorting of names

10 CLS                 ' Clear the screen
11 CLEAR               ' Delete the contents of all variables
12 DEFINT B, I-K, M-N
13 DEFLNG D-G
16 DEFSTR P-S
20 REM Than this number further starts the program code
30 DIM A$(9): DIM B(9)
40 N = 0
50 REM Place to return by choice
100 PRINT "Enter a name in " N; ". the matrix" : INPUT A$(N)
110 B(N) = LEN(A$(N))
120 N = N + 1
130 IF N <= 9 THEN GOTO 50
200 GOSUB 1100
210 N = 0
    FOR N = 0 TO 9
      PRINT N, A$(N)
      PRINT
    NEXT N
900 SLEEP
999 END                ' Completion of the programming code
1000 REM Than this number further start sub-programs
1100 I = 0: J = 0: N = 9
1200 REM Place to return by choice
     IF B(I) < B(J) THEN
       GOTO 1400
     ELSE
       nohigher = B(I): nodata$ = A$(I)
       B(I) = B(J): A$(I) = A$(J)
       B(J) = nohigher: A$(J) = nodata$
     END IF
1400 IF J < N THEN J = J + 1: GOTO 1200
1600 IF I < N THEN I = I + 1: J = I: GOTO 1200
2000 RETURN

In line 200 of the program is a call for the sub-program. Sub-programs always end with a RETURN command, to resume execution of the main program of the next line after the call sub-program, in this case from the line of 210.

If there is a need in a computer program to calculate several dozen times the same function, but each time with a different input variables, mathematical apparatus of functions in the program is well to set in the sub-program. Why?

It should be noted that it is not necessary to write the numbers of individual lines, as in the example shown in the display FOR-NEXT and IF-THEN-ELSE-END IF programming structures. How, then, the program jump on command GOTO? Read the Help pages (RTFM)!