JavaPython:List
| Java vs Python |
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Pythoni järjendile on Javas lähim sarnane andmetüüp kas array või ArrayList.
Python järjend --> Java array
An array is indexed like a Python list, with square brackets:
students[0] or letters[i][j].
Declaring an array does not create one. The declaration tells how many dimensions the array has, but never its size:
for example, char[][] letters.
To create one, use the word new, then its type and size;
new char[5][5].
Python has list literals:
[1, 2, 3, 4].
Java has two different syntaxes for array literals: In a declaration (only):
int[] numbers = {1, 2, 3, 4};Other places:
new int[] {1, 2, 3, 4}
Java has no equivalent to Python's list[i:j] notation.
Python järjend --> Java ArrayList
An ArrayList acts more like a Python list, but uses only object syntax. There are no literals.
ArrayList<String> languages = new ArrayList<String>();
languages.add("Python"); // append to list
String oldLanguage = languages.get(0);
languages.set(0, "Java");
Some additional methods: boolean isEmpty(), boolean contains(object), int size(), type remove(index).
Näide
| Java | Python |
|---|---|
| <syntaxhighlight lang="java" line="1" >
//arraylist is closest with list in python ArrayList<Integer> aList = new ArrayList<Integer>(); //add aList.add(1); aList.add(3); aList.add(2); aList.add(4); //index int n = aList.get(0); //get sub list List<Integer> subList = aList.subList(0, 2); //1, 3 </syntaxhighlight> |
<syntaxhighlight lang="python" line="2" >
aList = [] aList = [1, 'mike', 'john']
aList.append(2)
aList.extend(["new","list"]) print aList
aList = [0,1,2,3,4,5,6]
print len(aList)
print aList[2]
print aList[0:3]
print aList[2:]
print aList[-2]
aList[0] = 10 print aList
</syntaxhighlight> |