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Java - replace first 2 characters in string
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In this article, we would like to show you how to replace the first 2 characters in string in Java.
Quick solution:
xxxxxxxxxx1
String text = "ABCD";2
String replacement = "xy";3
String result = replacement + text.substring(2);4
5
System.out.println(result); // xyCDor:
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String text = "ABCD";2
String replacement = "xy";3
String result = replacement.concat(text.substring(2));4
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System.out.println(result); // xyCDor:
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String text = "ABCD";2
String replacement = "xy";3
String result = text.replaceAll("^.{2}", replacement);4
5
System.out.println(result); // xyCD
In this example, we will take the last 2 characters from the original string and add them to the end of the replacement.
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public class Example {2
3
public static void main(String[] args) {4
String text = "ABCD";5
String replacement = "xy";6
String result = replacement + text.substring(2);7
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System.out.println(result); // xyCD9
}10
}This approach is equivalent to the above one. Instead of + operator we concatenate the strings using concat() method.
xxxxxxxxxx1
public class Example {2
3
public static void main(String[] args) {4
String text = "ABCD";5
String replacement = "xyz";6
String result = replacement.concat(text.substring(3));7
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System.out.println(result); // xyCD9
}10
}In this example, we use string replaceAll() with "^.{2}" regex to replace the first 2 characters in the text string.
Regex explanation:
^- matches the beginning of the string,.- matches any character except linebreaks,{2}- matches the specified quantity of the previous token (in our case the.).
xxxxxxxxxx1
public class Example {2
3
public static void main(String[] args) {4
String text = "ABCD";5
String replacement = "xy";6
String result = text.replaceAll("^.{2}", replacement);7
8
System.out.println(result); // xyCD9
}10
}Note:
Regular expressions are slower than
substring()method.
