Java 中的 Java.lang.string.replace()方法
原文:https://www . geesforgeks . org/Java-lang-string-replace-method-Java/
以下是替换()方法的三个变体。本文对它们全部进行了描述，如下: 1。String replace() : 此方法返回一个新字符串，该字符串是用新字符替换字符串中所有出现的旧字符而得到的。
Syntax:
public String replace(char oldch, char newch)
Parameters:
oldch : the old character.
newch : the new character.
Return Value
It returns a string derived from this string by replacing every occurrence of oldch with newch.
// Java code to demonstrate the
// working of replace()
public class rep1 {
public static void main(String args[]) {
// Initialising String
String Str = new String("Welcome to geeksforgeeks");
// Using replace to replace characters
System.out.print("After replacing all o with T : " );
System.out.println(Str.replace('o', 'T'));
// Using replace to replace characters
System.out.print("After replacing all e with D : " );
System.out.println(Str.replace('e', 'D'));
}
}
输出:
After replacing all o with T : WelcTme tT geeksfTrgeeks
After replacing all e with D : WDlcomD to gDDksforgDDks
2。String replaceAll() : 此方法用给定的 replace_str 替换与给定正则表达式匹配的字符串的每个子字符串。
Syntax:
public String replaceAll(String regex, String replace_str)
Parameters:
regex: the regular expression to which this string is to be matched.
replace_str:the string which would replace found expression.
Return Value
This method returns the resulting String.
// Java code to demonstrate the
// working of replaceAll()
public class rep2 {
public static void main(String args[]) {
// Initialising String
String Str = new String("Welcome to geeksforgeeks");
// original string
System.out.print("Original String : " );
System.out.println(Str);
// Using replaceAll to replace regex with replace_str
System.out.print("After replacing regex with replace_str : " );
System.out.println(Str.replaceAll("(.*)geeks(.*)", "ASTHA TYAGI"));
}
}
输出:
Original String : Welcome to geeksforgeeks
After replacing regex with replace_str : ASTHA TYAGI
3。String replaceFirst() : 该方法用给定的 replace_str 替换该字符串中与给定正则表达式匹配的第一个子字符串。
**Syntax**
public String replaceFirst(String regex, String replace_str)
**Parameters**
**regex :**the regular expression to which this string is to be matched.
**replace_str :** the string which would replace found expression.
**Return Value :**
This method returns a resulting String.
// Java code to demonstrate the
// working of replaceFirst()
public class rep3 {
public static void main(String args[]) {
// Initialising String
String Str = new String("Welcome to geeksforgeeks");
// original string
System.out.print("Original String : " );
System.out.println(Str);
// Using replaceFirst to replace regex with replace_str
// Replaces 1st occurrence of geeks with ASTHA
System.out.print("After replacing 1st occurrence of regex with replace_str : " );
System.out.println(Str.replaceFirst("geeks", "ASTHA"));
}
}
输出:
Original String : Welcome to geeksforgeeks
After replacing 1st occurrence of regex with replace_str : Welcome to ASTHAforgeeks
本文由 Astha Tyagi 供稿。如果你喜欢 GeeksforGeeks 并想投稿，你也可以使用contribute.geeksforgeeks.org写一篇文章或者把你的文章邮寄到 contribute@geeksforgeeks.org。看到你的文章出现在极客博客主页上，帮助其他极客。 如果你发现任何不正确的地方，或者你想分享更多关于上面讨论的话题的信息，请写评论。
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