Here we will see Java string replace examples with replacing the string, replacing characters, replacing whitespace vowels, and using a regular expression to replace string and substring.
Java string replace Example: use of replace()
Java String replace() is used to replace substring in given string.
public class JavaString {
public static void main(String[] args) {
String s1 = " My Name is Joker";
String s2 = s1.replace("Joker", "Poker");
System.out.println("Old String : " + s1);
System.out.println("New String : " + s2);
}
}
In this example, Joker is replaced with Poker and the updated string is stored in s2.
Old String : My Name is Joker
New String : My Name is Poker
Java replace multiple characters in string | replaceall java
In the following example, we replace all occurrences of This to It using relpaceAll().
public class ReplaceAllExample {
public static void main(String[] args) {
String s1 = "This is a ball. This is a red color ball. This is a heavey ball";
String s2 = s1.replaceAll("This", "It");
System.out.println("Old String :" + s1);
System.out.println("New String :" + s2);
}
}
Here we are replacing This with It. This comes 3 times using replaceAll() we can replace multiple occurrences of text.
Old String :This is a ball. This is a red color ball. This is a heavey ball New String :It is a ball. It is a red color ball. It is a heavey ball
String replace java Example
public class StringReplace {
public static void main(String[] args) {
String s1 = "Hello how are you";
String s2 = s1.replace("how are you", "I am fine");
System.out.println("Old String : " + s1);
System.out.println("New String : " + s2);
}
}
Old String : Hello how are you New String : Hello I am fine
java string replace substring
public class Substring {
public static void main(String[] args) {
String s1 = "2022 July04 12:08 PM";
String s2 = s1.replace("PM", "AM");
System.out.println("Old String : " + s1);
System.out.println("New String : " + s2);
}
}
Old String : 2022 July04 12:08 PM New String : 2022 July04 12:08 AM
how to replace a character in a string in java | replace character in string java
Replacing a single character from a string is simple by using replace().
The following example illustrates the same
public class ReplaceCharacter {
public static void main(String[] args) {
String s1 = "Alephant";
String s2 = s1.replace('A', 'E');
System.out.println("Old String : " + s1);
System.out.println("New String : " + s2);
}
}
Old String : Alephant New String : Elephant
java string replace regex
A regular expression is one of the powerful mechanisms in Java. using regular expressions we can reduce our code.
How to remove special characters from a string in java
Java replaceall regex example
public class StringRegx {
public static void main(String[] args) {
String s1 = "This123is@a99string#example ";
String s2 = s1.replaceAll("[^a-zA-Z]+", " ");
System.out.println("Old String : " + s1);
System.out.println("New String : " + s2);
}
}
Old String : This123is@a99string#example New String : This is a string example
how to replace a character in a string in java without using replace method
This may be your interview question. In a simple way we can use replace() but we don’t have to use it.
To solve this we get substring before character and substring after character then we combined. str1+char+str2.
public class ReplaceChar {
public static void main(String[] args) {
String s1 = " My Name is Joker";
char find = 'J';
char replace = 'P';
int i = s1.indexOf(find);
String str1 = s1.substring(0, i);
String str2 = s1.substring(i + 1);
String s2 = str1 + replace + str2;
System.out.println("Old String : " + s1);
System.out.println("New String : " + s2);
}
}
Old String : My Name is Joker New String : My Name is Poker
java replace string with another string
Here One String is replaced with another string using replaceAll().
public class JavaSubstring {
public static void main(String[] args) {
String s1 = "This is a red doll";
String s2 = s1.replaceAll("red doll", "yellow shirt");
System.out.println("Old String :" + s1);
System.out.println("New String :" + s2);
}
}
Old String :This is a red doll New String :This is a yellow shirt
Replace vowels in a string java
Here we considered both upper and lower case vowels and replaced it with -. Here replaceAll() method is used to replace.
public class JavaSubstring {
public static void main(String[] args) {
String s1 = "This is a red doll";
String s2 = s1.replaceAll("[AaEeIiOoUu]", "-");
System.out.println("Old String :" + s1);
System.out.println("New String :" + s2);
}
}
Old String :This is a red doll New String :Th-s -s - r-d d-ll
Java string replace whitespace | Replace whitespace in java
White spaces are spaces between characters and words it also includes \t \r \n. To remove white spaces we use the \\s pattern that includes all-white spaces.
public class JavaSubstring {
public static void main(String[] args) {
String s1 = "T h i s i s a r e d d o l l";
String s2 = s1.replaceAll("\\s","");
System.out.println("Old String :" + s1);
System.out.println("New String :" + s2);
}
}
Old String :T h i s i s a r e d d o l l New String :Thisisareddoll