Basic

BASIC：昔日编写程序时的美好时光！美妙的感觉！ 10 INPUT A 20 B = SIN(A) 30 PRINT ANSWER: , B 40 END I think everybody in this country should learn how to program a computer, should learn a computer language. Because it teaches you how to think, it\'s like going to a law school. I don\'t think anybody should be a lawyer, but I think going to a law school actually be useful, \'cause it taches you how to think. - 乔布斯 BASIC 用户指南: • PRINT 10 PRINT HELLO WORLD ! 20 END • INPUT 10 INPUT “A=”, A 20 PRINT A 30 END • IF...THEN... 数值比较: 10 INPUT A 20 IF A＞90 THEN B=“A” 30 PRINT B 40 END 运算符: ＞ 大于 ＜ 小于 ＞= 大于或等于 =＞ 等于或大于 ＜= 小于或等于 =＜ 等于或小于 = 等于 == 等于 ＜＞ 不等于 != 不等于 THEN 后面可以有 GOTO, GOSUB, INPUT, PRINT. 字符串比较: 10 INPUT A 20 IF A=“TOM” THEN PRINT “BOY” 30 END 运算符: = is == is ＜＞ is not != is not • FOR...NEXT... 10 FOR I=1 TO 4 STEP 2 20 PRINT “HELLO”, I 30 NEXT I 40 END STEP： 步进。默认为1。 FOR...NEXT... 可以嵌套. 10 FOR I=1 TO 5 20 FOR J=1 TO 4 30 PRINT I, J 40 NEXT J 50 NEXT I 60 END • GOTO 10 ... 20 ... 30 ... 40 GOTO 10 50 ... • GOSUB 10 PRINT “H” 20 GOSUB 100 30 PRINT “L” 40 END 100 PRINT “A” 110 RETURN • SOUND 10 SOUND C, M, 0.5 播放钢琴C调 do，0.5秒钟。 音调: C, C#, D, D#, E, F, F#, G, G#, A, A#, B 音阶: L (low), M (middle), H (high) C, D, E, F, G, A, B 也可以表示成简谱形式： 1, 2, 3, 4, 5, 6, 7. (C# 为 1#). • TEXT 10 TEXT “HELLO”, x, y, size (x,y): 字符串 “HELLO” 的坐标。 • CIRCLE 10 CIRCLE x, y, radius (x,y): 圆心坐标。 • RECTANGLE 10 RECT x, y, width, height (x,y): 矩形左上角坐标。 • LINE 10 LINE x1, y1, x2, y2 (x1,y1): 起点坐标。 (x2,y2): 终点坐标。 • POINT 10 POINT x, y (x,y): 点坐标。 • CLR: 清图形屏 • CLS: 清编辑屏. • DELAY 10 DELAY 0.5 0.5:延时0.5秒。 • CURVE 10 CURVE x, y, radius, 0, PI 0: 起始角。 PI: 终位角。 以圆心（x,y）顺时针画出曲线。 • 数学方程: SIN(X), COS(X), TAN(X), COT(X), ASIN(X), ACOS(X), ATAN(X), SINH(X), COSH(X), TANH(X), ASINH(X), ACOSH(X), ATANH(X). SQR(X): square root of x. ABS(X): absolute value of x. FCT(X): x factorial. LOG(X): natural logarithm of x. LOG10(X): base-10 logarithm of x. LOG2(X) :base-2 logarithm of x. EXP(X): base-e exponential of x. ERF(X): the error function of x. ERFC(X): the complementary error function of x. ROUND(X) :integral nearest to x. CEIL(X): the smallest integral that is not less than x. FLOOR(X): the largest integral that is not greater than x. TGAMMA(X): the gamma function of x. LGAMMA(X): the natural logarithm of the absolute value of the gamma function of x. • 固有变量: INKEY : once a key is pressed, the value of INKEY changes. RND : a random number. PI : π • 一些技巧: 1. Undo & Redo typing on iPhone with a shake. 2. Copy an Emoji or some character from other places (like Notes), then paste them on the edit window. 3. Exponentiation is expressed as X^Y.