创建一个在Java中存储字符串和整数的数组 [英] Creating an array that stores strings and integers in java

问题描述

我想创建一个存储公司股票名称(字符串)和值(整数)的数组，但是我不知道该怎么做.

I would like to create an array that stores the names (String) and values (integer) of company stocks, but I don't know how to go about it.

推荐答案

Object [] 可以容纳 String 和 Integer 对象.这是一个简单的示例:

An Object[] can hold both String and Integer objects. Here's a simple example:

    Object[] mixed = new Object[2];
    mixed[0] = "Hi Mum";
    mixed[1] = Integer.valueOf(42);
    ...
    String message = (String) mixed[0];
    Integer answer = (Integer) mixed[1];

但是，如果您像这样使用 Object [] 放置，则通常需要在访问元素时使用 instanceof 和/或键入强制类型转换.

However, if you put use an Object[] like this, you will typically need to use instanceof and / or type casts when accessing the elements.

任何通常涉及 instanceof 和/或类型强制转换的设计都应引起怀疑.在大多数情况下，有一种更好的方法(更面向对象，更高效，更不易碎)来达到相同的目的.

Any design that routinely involves instanceof and/or type casts needs to be treated with suspicion. In most cases, there is a better (more object-oriented, more efficient, less fragile) way of achieving the same ends.

在您的特定用例中，听起来您真正需要的是一个映射对象，该对象从 String (名称)映射到 Integer (股票数量).关于Java的好处是，已有的库类提供了此功能.例如 HashMap< K，V> 类，其中 String 是键类型，而 Integer 是值类型.

In your particular use-case, it sounds like what you really need is a mapping object that maps from String (names) to Integer (numbers of stocks). And the nice thing about Java is that there are existing library classes that provide this functionality; e.g. the HashMap<K,V> class, with String as the key type and Integer as the value type.

另一种可能是一些自定义或通用对类的数组， List 或 Set .这些对 Map 类型具有不同的语义属性.

Another possibility might be an array, List or Set of some custom or generic pair class. These have different semantic properties to Map types.

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