Java的String如何取下前几个字符放到后面?

2025-04-02 23:54:07
推荐回答(3个)
回答1:

你可以参看String类的DOC

public String replace(char oldChar,
char newChar)返回一个新的字符串,它是通过用 newChar 替换此字符串中出现的所有 oldChar 而生成的。
如果 oldChar 在此 String 对象表示的字符序列中没有出现,则返回对此 String 对象的引用。否则,创建一个新的 String 对象,用来表示与此 String 对象表示的字符序列相等的字符序列,除了每个出现的 oldChar 都被一个 newChar 替换之外。

public String replaceFirst(String regex,
String replacement)使用给定的 replacement 字符串替换此字符串匹配给定的正则表达式的第一个子字符串。

....
不一一列举了!

回答2:

string 类型是不可变类型,也就是说该类型一旦被创建,就不可更改(是堆里内容不可更改),
so, 要完成这个功能有两个方法:
1. 利用字符串拼接
2. 利用StringBuffer等类来完成
具体代码就不贴了...

回答3:

.'......
String str="我的爱520";
String str1=str.substring(0,2);
str=str.substring(3,5)+str1;
....
结果即可输出:520我的爱

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