[SAMPLE9] SAMPLE
10 REM SAMPLE9
100 *ENTRY
110 INPUT "0=END N= ";N
120 SG=SGN(N) +1
130 ON SG GOTO *ZERO,*PLUS
140 *MINUS:PRINT "MINUS!":GOTO *ENTRY
150 *ZERO:PRINT "ZERO!":GOTO 900
160 *PLUS:PRINT "PLUS!":GOTO *ENTRY
900 END
120 入力値に対するSGN関数の値-1,0,+1を,0,1,2に変換。
130 入力値の負,0,正に従って,*MINUS,
*ZERO,*PLUSに飛ぶ。