编辑“︁BASIC”︁（章节）

==BASIC語言的種類==
以下是同樣的執行結果，但用不同時期的BASIC的方式所寫的範例。

===行號類型（非結構化）===
這是第一代的BASIC，例如早期[[BASICA]]、[[GW-BASIC]]……等，BASIC直譯器。這類的BASIC程式的特徵，就是每一行的程式碼前面都有一個數字作為「[[行號 (程式語言)|行號]]」。由於這種類型的BASIC程式的寫法，很容易濫用GOTO的跳躍指令，以及程式碼沒有辦法使用到縮排去區分區段，因此很容易導致[[面条式代码]]。

<syntaxhighlight lang="QBasic">
10 INPUT "What is your name: ", U$
20 PRINT "Hello "; U$
30 INPUT "How many stars do you want: ", N
40 S$ = ""
50 FOR I = 1 TO N
60 S$ = S$ + "*"
70 NEXT I
80 PRINT S$
90 INPUT "Do you want more stars? ", A$
100 IF LEN(A$) = 0 THEN GOTO 90
110 A$ = LEFT$(A$, 1)
120 IF A$ = "Y" OR A$ = "y" THEN GOTO 30
130 PRINT "Goodbye "; U$
140 END
</syntaxhighlight>

===無行號類型（結構化）===
這是第二代的BASIC，例如[[QuickBASIC]]、[[PowerBASIC]]。這時期，同時有功能相近的直譯器與編譯器的版本出現。這類的BASIC程式的特徵，是不使用行號，改使用標籤作為跳躍點（仍有GOTO指令，但已可使用其他寫法可完全避開使用GOTO），與使用函數或副程式的方式，以及可使用縮排，將程式結構化。<ref name="GBvsQB">{{cite web|url=http://support.microsoft.com/kb/73084|title=Differences Between GW-BASIC and QBasic|date=2003-05-12|accessdate=2008-06-28|author=|archive-date=2013-10-19|archive-url=https://web.archive.org/web/20131019181140/http://support.microsoft.com/kb/73084|dead-url=no}}</ref>

<syntaxhighlight lang="QBasic">
INPUT "What is your name: ", UserName$
PRINT "Hello "; UserName$
DO
  INPUT "How many stars do you want: ", NumStars
  Stars$ = STRING$(NumStars, "*") 
  PRINT Stars$
  DO
    INPUT "Do you want more stars? ", Answer$
  LOOP UNTIL Answer$ <> ""
  Answer$ = LEFT$(Answer$, 1)
LOOP WHILE UCASE$(Answer$) = "Y"
PRINT "Goodbye "; UserName$
</syntaxhighlight>

===物件導向化===
這是第三代的BASIC，例如[[Visual Basic]]、[[REALbasic]]、[[StarOffice Basic]]。這類的BASIC程式的特徵，是導入[[類別 (電腦科學)|類別]]（Class）的應用，使用[[物件導向]]的[[繼承 (電腦科學)|繼承]]與程式碼封裝寫法。通常也使用「[[事件驅動]]」的寫法，雖然下面這個[[Visual Basic .NET]]的範例並不是用到事件驅動。

<syntaxhighlight lang="vbnet"> 
Public Class StarsProgram
    Public Shared Sub Main()
        Dim UserName, Answer, stars As String, NumStars As Integer
        Console.Write("What is your name: ")
        UserName = Console.ReadLine()
        Console.WriteLine("Hello {0}", UserName)
        Do
            Console.Write("How many stars do you want: ")
            NumStars = CInt(Console.ReadLine())
            stars = New String("*", NumStars)
            Console.WriteLine(stars)
            Do
                Console.Write("Do you want more stars? ")
                Answer = Console.ReadLine()
            Loop Until Answer <> ""
            Answer = Answer.Substring(0, 1)
        Loop While Answer.ToUpper() = "Y"
        Console.WriteLine("Goodbye {0}", UserName)
    End Sub
End Class
</syntaxhighlight>