Declaración del problema: dada una string, extraiga la substring encerrada entre comillas simples (‘) usando Java Regex.
Java regex es una API para la coincidencia de patrones con expresiones regulares. ‘java.util.regex’ es una clase utilizada para
- Interfaz
- MatchResult: el resultado de una operación de coincidencia
- Clases
- Matcher: un motor que realiza operaciones de coincidencia en una secuencia de caracteres mediante la interpretación de un patrón .
- Patrón: una representación compilada de una expresión regular.
Ilustración:
Input : "Out of this String required only is 'Geeks for Geeks' only'" Output : Geeks for Geeks Input : "The data wanted is'Java Regex'" Output : Java Regex
Ejemplo
Java
// Java program to demonstrate extracting
// substring enclosed in single quotes
// Importing Matcher and Pattern class
// from regex class of java.util package
// Importing input output classes
import java.io.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
// Class
public class GFG {
// Main driver method
public static void main(String[] args)
{
// Custom input
String string1
= "Out of this String I want 'Geeks for Geeks' only";
// Desired custom output
String string2
= "The data that I want is'Java Regex'";
// Paranthesis indicate it is a group and signifies
// it can have substring enclosed in single quote
Pattern p = Pattern.compile(".*'([^']*)'.*");
// This method returns a pattern object
// Calling matcher() method of pattern object
// and passing input character sequence
Matcher m1 = p.matcher(string1);
Matcher m2 = p.matcher(string2);
// Printing complete entered string 1
System.out.println("String to be extracted : "
+ string1);
// Condition check using matches() method which
// looks out for content if any in single quote
if (m1.matches()) {
// Print the required sub-string
System.out.println("Extracted part : "
+ m1.group(1));
}
// New line
System.out.println();
// Printing complete entered string 2
System.out.println("String to be extracted : "
+ string2);
// Condition check using matches() method which
// looks out for content if any in single quote
if (m2.matches()) {
// Print the required sub-string
System.out.println("Extracted part : "
+ m2.group(1));
}
}
}
String to be extracted : Out of this String I want 'Geeks for Geeks' only Extracted part : Geeks for Geeks String to be extracted : The data that I want is'Java Regex' Extracted part : Java Regex
Publicación traducida automáticamente
Artículo escrito por uvrajanshuman y traducido por Barcelona Geeks. The original can be accessed here. Licence: CCBY-SA