El Reemplazo de clase de cadena Java () El método devuelve una cadena que reemplaza todos los caracteres o CharSequence antiguos por nuevos caracteres o CharSequence.
Desde JDK 1.5, se introduce un nuevo método replace() que nos permite reemplazar una secuencia de valores de caracteres.
Firma
Hay dos tipos de métodos replace() en la clase Java String.
public String replace(char oldChar, char newChar) public String replace(CharSequence target, CharSequence replacement)
El segundo método replace() se agrega desde JDK 1.5.
Parámetros
viejoChar : personaje antiguo
nuevoChar : nuevo personaje
objetivo : secuencia objetivo de caracteres
reemplazo : secuencia de reemplazo de caracteres
Devoluciones
cadena reemplazada
Lanzamientos de excepción
NullPointerException: si el reemplazo o el objetivo es igual a nulo.
Implementación interna
public String replace(char oldChar, char newChar) { if (oldChar != newChar) { int len = value.length; int i = -1; char[] val = value; /* avoid getfield opcode */ while (++i <len) { if (val[i]="=" oldchar) break; } (i < len) char buf[]="new" char[len]; for (int j="0;" i; j++) buf[j]="val[j];" while c="val[i];" buf[i]="(c" =="oldChar)" ? newchar : c; i++; return new string(buf, true); this; pre> <pre> public String replace(CharSequence target, CharSequence replacement) { return Pattern.compile(target.toString(), Pattern.LITERAL).matcher( this).replaceAll(Matcher.quoteReplacement(replacement.toString())); } </pre> <h2>Java String replace(char old, char new) method example</h2> <p> <strong>FileName:</strong> ReplaceExample1.java</p> <pre> public class ReplaceExample1{ public static void main(String args[]){ String s1='javatpoint is a very good website'; String replaceString=s1.replace('a','e');//replaces all occurrences of 'a' to 'e' System.out.println(replaceString); }} </pre> <span> Test it Now </span> <p> <strong>Output:</strong> </p> <pre> jevetpoint is e very good website </pre> <h2>Java String replace(CharSequence target, CharSequence replacement) method example</h2> <p> <strong>FileName:</strong> ReplaceExample2.java</p> <pre> public class ReplaceExample2{ public static void main(String args[]){ String s1='my name is khan my name is java'; String replaceString=s1.replace('is','was');//replaces all occurrences of 'is' to 'was' System.out.println(replaceString); }} </pre> <span> Test it Now </span> <p> <strong>Output:</strong> </p> <pre> my name was khan my name was java </pre> <h2>Java String replace() Method Example 3</h2> <p> <strong>FileName:</strong> ReplaceExample3.java</p> <pre> public class ReplaceExample3 { public static void main(String[] args) { String str = 'oooooo-hhhh-oooooo'; String rs = str.replace('h','s'); // Replace 'h' with 's' System.out.println(rs); rs = rs.replace('s','h'); // Replace 's' with 'h' System.out.println(rs); } }</pre> <p> <strong>Output:</strong> </p> <pre>oooooo-ssss-oooooo oooooo-hhhh-oooooo </pre> <h2>Java String replace() Method Example 4</h2> <p>The replace() method throws the NullPointerException when the replacement or target is null. The following example confirms the same.</p> <p> <strong>FileName:</strong> ReplaceExample4.java</p> <pre> public class ReplaceExample4 { // main method public static void main(String argvs[]) { String str = 'For learning Java, JavaTpoint is a very good site.'; int size = str.length(); System.out.println(str); String target = null; // replacing null with JavaTpoint. Hence, the NullPointerException is raised. str = str.replace(target, 'JavaTpoint '); System.out.println(str); } } </pre> <p> <strong>Output:</strong> </p> <pre> For learning Java, JavaTpoint is a very good site. Exception in thread 'main' java.lang.NullPointerException at java.base/java.lang.String.replace(String.java:2142) at ReplaceExample4.main(ReplaceExample4.java:12) </pre> <hr></len)> Ejemplo de método de reemplazo de cadena Java (char antiguo, char nuevo)
Nombre del archivo: ReplaceExample1.java
public class ReplaceExample1{ public static void main(String args[]){ String s1='javatpoint is a very good website'; String replaceString=s1.replace('a','e');//replaces all occurrences of 'a' to 'e' System.out.println(replaceString); }} Pruébalo ahora Producción:
jevetpoint is e very good website
Ejemplo de método de reemplazo de cadena Java (destino CharSequence, reemplazo CharSequence)
Nombre del archivo: ReplaceExample2.java
public class ReplaceExample2{ public static void main(String args[]){ String s1='my name is khan my name is java'; String replaceString=s1.replace('is','was');//replaces all occurrences of 'is' to 'was' System.out.println(replaceString); }} Pruébalo ahora Producción:
my name was khan my name was java
Ejemplo 3 del método Java String replace()
Nombre del archivo: ReplaceExample3.java
public class ReplaceExample3 { public static void main(String[] args) { String str = 'oooooo-hhhh-oooooo'; String rs = str.replace('h','s'); // Replace 'h' with 's' System.out.println(rs); rs = rs.replace('s','h'); // Replace 's' with 'h' System.out.println(rs); } } Producción:
oooooo-ssss-oooooo oooooo-hhhh-oooooo
Ejemplo 4 del método Java String replace()
El método replace() genera NullPointerException cuando el reemplazo o el destino es nulo. El siguiente ejemplo confirma lo mismo.
Nombre del archivo: ReplaceExample4.java
public class ReplaceExample4 { // main method public static void main(String argvs[]) { String str = 'For learning Java, JavaTpoint is a very good site.'; int size = str.length(); System.out.println(str); String target = null; // replacing null with JavaTpoint. Hence, the NullPointerException is raised. str = str.replace(target, 'JavaTpoint '); System.out.println(str); } } Producción:
For learning Java, JavaTpoint is a very good site. Exception in thread 'main' java.lang.NullPointerException at java.base/java.lang.String.replace(String.java:2142) at ReplaceExample4.main(ReplaceExample4.java:12)