创建Java数组时使用尖括号和方括号方法的区别 [英] Difference between using angle and square bracket methods in creation of Java Arrays

问题描述

我最近刚开始使用Java，并且已经开始使用Arrays.据我所知，有两种创建数组的方法.

I've just recently started with Java and have gotten to Arrays. from what I can tell there are two ways of creating Arrays.

第一种方法对我来说最有意义，它来自python背景.

The first method makes the most sense to me coming from a python background.

type[] ArrayName;

即

int[] agesOfParticipants;

但是，许多在线资源使用另一种创建数组的方法.

However a lot of resources online use a different method of creating arrays.

ArrayList<ArrayType> Name = new ArrayList<ArrayType>;

这不仅有所不同，而且与我可以说的术语ArrayList根据情况至少是部分可互换的.例如，在此响应中，ArrayList被先前声明的类A取代.

not only is this different but from what I can tell the term ArrayList is at least partially interchangeable depending on circumstance. For instance in this response ArrayList is replaced by class A, which is declared earlier.

 A<String> obj=new A<String>();

对不起，如果这一切都是基本的东西，但是我找不到真正能够将两者区分开的地方.

Sorry if this is all basic stuff, but I can't find anywhere that really distinguishes between the two.

推荐答案

在Java对象中，使用 new 关键字

In java objects are created using new keyword

创建新的大小为 10 的 Integer 数组，该数组由方括号 []

creating new Integer array with size 10, array consists of square brackets []

Integer[] array = new Integer[10];
System.out.println(Arrays.toString(array)); // print array values `[..]`

创建值为10的 Integer 对象

Integer object = new Integer(10);
System.out.println(object); // print object value 10

创建仅包含 Integer 值

List<Integer> list = new ArrayList<>();
list.add(object);
System.out.println(object); // prints list with values [10]

尖括号<> 是泛型，用于定义同类对象(例如，仅整数列表)

Angular brackets <> are Generics, that are used to define homogeneous type of objects (for example list of Integers only)

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