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Java Program to Print first letter of each word using regex
In this article, we will understand how to print first letter of each word using regex. A regular expression is a sequence of characters that forms a search pattern. A regular expression can be a single character, or a more complicated pattern.
A regular expression helps you match or find other strings or sets of strings, using a specialized syntax held in a pattern. They can be used to search, edit, or manipulate text and data.
Below is a demonstration of the same −
Suppose our input is −
Input String_1: Java Program Input String_2: Joy of learning
The desired output would be −
Result_1: JP Result_2: Jol
Algorithm
Step 1 - START Step 2 - Declare two string values namely input_string_1 and input_string_2. Declare a regex Pattern namely string_pattern and a Matcher object namely string_matcher. Step 3 - Define the values. Step 4 - Using a while-loop, compute string_matcher.group() to fetch the first letter of each word. Step 5 - Display the result Step 6 - Stop
Example 1
Here, we bind all the operations together under the ‘main’ function.
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Regex {
public static void main(String[] args) {
System.out.println("Required packages have been imported");
String input_string_1 = "Java Program";
System.out.println("\nThe first string is defined as: " +input_string_1);
Pattern string_pattern = Pattern.compile("\b[a-zA-Z]");
Matcher string_matcher = string_pattern.matcher(input_string_1);
System.out.println("The first letters of the string is : ");
while (string_matcher.find())
System.out.print(string_matcher.group());
System.out.println();
String input_string_2 = "Joy of learning";
System.out.println("\nThe second string is defined as: " +input_string_2);
Matcher string_matcher_2 = string_pattern.matcher(input_string_2);
System.out.println("The first letters of the string is : ");
while (string_matcher_2.find())
System.out.print(string_matcher_2.group());
System.out.println();
}
}Output
Required packages have been imported The first string is defined as: Java Program The first letters of the string is : JP The second string is defined as: Java Program The first letters of the string is : Jol
Example 2
Here, we encapsulate the operations into functions exhibiting object-oriented programming.
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Regex {
static void print_regex_string(String s) {
Pattern string_pattern = Pattern.compile("\b[a-zA-Z]");
Matcher string_matcher = string_pattern.matcher(s);
System.out.println("The first letters of the string is : ");
while (string_matcher.find())
System.out.print(string_matcher.group());
System.out.println();
}
public static void main(String[] args) {
System.out.println("Required packages have been imported");
String input_string_1 = "Java Program";
System.out.println("\nThe first string is defined as: " +input_string_1);
print_regex_string(input_string_1);
String input_string_2 = "Joy of learning";
System.out.println("\nThe second string is defined as: " +input_string_1);
print_regex_string(input_string_2);
}
}Output
Required packages have been imported The first string is defined as: Java Program The first letters of the string is : JP The second string is defined as: Java Program The first letters of the string is : Jol
Updated on: 29-Mar-2022
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