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For Schleife

Programmiersprachen können Code-Teile mehrfach nacheinander ausführen. In Python gibt es dabei zwei Konzepte. Die for Schleife und die while Schleife.

Die for Schleife kann man sich wie ein Ticket-Schalter vorstellen. Der Verkäufer am Schalter bedient der Reihe nach jede Person in der Warteschlange und wiederholt jedesmal dieselbe Aufgabe: den Kunden bedienen

Warteschlange

In Python wird die Warteschleife als Liste in eckigen Klammern geschrieben:

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for person in ['Jack', 'Maria', 'Reto']:
    print(f'Guten Tag {person}, wie kann ich helfen?')
    print('...')
    print('Auf wiedersehen') 
 
 
הההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההה
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Die Personen Jack, Maria und Reto werden nacheinander begrüsst, bedient und verabschiedet:

Guten Tag Jack, wie kann ich helfen?
...
Auf wiedersehen.

Guten Tag Maria, wie kann ich helfen?
...
Auf wiedersehen.

Guten Tag Reto, wie kann ich helfen?
...
Auf wiedersehen.

Um einen beliebigen Code-Teil mehrfach nacheinander auszuführen, können wir nun auch Zahlen als Warteschleife verwenden:

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from turtle import *
for counter in [0, 1, 2, 3]:
    forward(100)
    left(90) 
 
 
הההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההה
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Für jede Zahl wird der Code-Teil wiederholt:

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python

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from turtle import *
# 0
forward(100)
left(90)
# 1
forward(100)
left(90)
# 2
forward(100)
left(90)
# 3
forward(100)
left(90) 
 
 
הההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההה
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Oder in Kurzschreibweise:

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python

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from turtle import *
for counter in range(4):
    forward(100)
    left(90) 
 
 
הההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההה
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wobei range(4) eine Warteschleife mit 4 Elementen erzeugt.

Was ist die Ausgabe des folgenden Programms?

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from turtle import *
penup()
goto(-30, 0)
pendown()
for counter in range(8):
    forward(60)
    left(45)
penup()
goto(-30, 100)
pendown()
setheading(180)     # Orientierung nach links: ◀️
for counter in range(8):
    forward(5)
    right(45)
penup()
goto(30, 100)
pendown()
setheading(0)       # Orientierung nach rechts: ▶️
 
 
הההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההה
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Was ist die Ausgabe des folgenden Programms?