通过索引获取字符串字符 - Java [英] Get string character by index - Java

问题描述

我知道如何计算字符串中某个字符或数字的索引，但有没有任何预定义的方法可以用来给我 nth 位置的字符？所以在字符串foo中，如果我要求索引为0的字符，它将返回f。

I know how to work out the index of a certain character or number in a string, but is there any predefined method I can use to give me the character at the nth position? So in the string "foo", if I asked for the character with index 0 it would return "f".

注意 - 在上面的问题中，由字符我不是指char数据类型，而是字符串中的字母或数字。这里重要的是我在调用方法时没有收到char，而是一个字符串（长度为1）。我知道substring（）方法，但我想知道是否有更简洁的方法。

Note - in the above question, by "character" I don't mean the char data type, but a letter or number in a string. The important thing here is that I don't receive a char when the method is invoked, but a string (of length 1). And I know about the substring() method, but I was wondering if there was a neater way.

推荐答案

你的方法重新寻找的是 charAt 。这是一个例子：

The method you're looking for is charAt. Here's an example:

String text = "foo";
char a_char = text.charAt(0);
System.out.println(a_char); // Prints f

有关详细信息，请参阅 上的Java文档String.charAt 。如果您想要另一个简单的教程，请这个或这一个。

For more information, see the Java documentation on String.charAt. If you want another simple tutorial, this one or this one.

如果您不想要结果作为 char 数据类型，而不是字符串，您将使用 Character.toString 方法：

If you don't want the result as a char data type, but rather as a string, you would use the Character.toString method:

String text = "foo";
String a_letter = Character.toString(text.charAt(0));
System.out.println( a_letter ); // Prints f

如果您想了解有关字符的更多信息 class和 toString 方法，我从关于Character.toString的文档。

If you want more information on the Character class and the toString method, I pulled my info from the documentation on Character.toString.

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