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Java String replace()

The Java String class replace() метод връща низ, заместващ всички стари char или CharSequence с нови char или CharSequence.

От JDK 1.5 е въведен нов метод replace(), който ни позволява да заменим последователност от char стойности.

Подпис

Има два типа replace() методи в класа Java String.

 public String replace(char oldChar, char newChar) public String replace(CharSequence target, CharSequence replacement) 

Вторият метод replace() е добавен от JDK 1.5.

numpy точка

Параметри

oldChar : стар характер

newChar : нов герой

мишена : целева последователност от знаци

замяна : заместваща последователност от знаци

Се завръща

заменен низ

Изключение Хвърляния

NullPointerException: ако заместването или целта е равно на нула.

Вътрешно изпълнение

 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=&apos;javatpoint is a very good website&apos;; String replaceString=s1.replace(&apos;a&apos;,&apos;e&apos;);//replaces all occurrences of &apos;a&apos; to &apos;e&apos; 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=&apos;my name is khan my name is java&apos;; String replaceString=s1.replace(&apos;is&apos;,&apos;was&apos;);//replaces all occurrences of &apos;is&apos; to &apos;was&apos; 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 = &apos;oooooo-hhhh-oooooo&apos;; String rs = str.replace(&apos;h&apos;,&apos;s&apos;); // Replace &apos;h&apos; with &apos;s&apos; System.out.println(rs); rs = rs.replace(&apos;s&apos;,&apos;h&apos;); // Replace &apos;s&apos; with &apos;h&apos; 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 = &apos;For learning Java, JavaTpoint is a very good site.&apos;; int size = str.length(); System.out.println(str); String target = null; // replacing null with JavaTpoint. Hence, the NullPointerException is raised. str = str.replace(target, &apos;JavaTpoint &apos;); System.out.println(str); } } </pre> <p> <strong>Output:</strong> </p> <pre> For learning Java, JavaTpoint is a very good site. Exception in thread &apos;main&apos; java.lang.NullPointerException at java.base/java.lang.String.replace(String.java:2142) at ReplaceExample4.main(ReplaceExample4.java:12) </pre> <hr></len)>

Java String replace(char old, char new) пример за метод

Име на файл: ReplaceExample1.java

 public class ReplaceExample1{ public static void main(String args[]){ String s1=&apos;javatpoint is a very good website&apos;; String replaceString=s1.replace(&apos;a&apos;,&apos;e&apos;);//replaces all occurrences of &apos;a&apos; to &apos;e&apos; System.out.println(replaceString); }} 
Тествайте сега

Изход:

 jevetpoint is e very good website 

Java String replace(CharSequence target, CharSequence replacement) пример за метод

Име на файл: ReplaceExample2.java

 public class ReplaceExample2{ public static void main(String args[]){ String s1=&apos;my name is khan my name is java&apos;; String replaceString=s1.replace(&apos;is&apos;,&apos;was&apos;);//replaces all occurrences of &apos;is&apos; to &apos;was&apos; System.out.println(replaceString); }} 
Тествайте сега

Изход:

 my name was khan my name was java 

Java String replace() метод Пример 3

Име на файл: ReplaceExample3.java

 public class ReplaceExample3 { public static void main(String[] args) { String str = &apos;oooooo-hhhh-oooooo&apos;; String rs = str.replace(&apos;h&apos;,&apos;s&apos;); // Replace &apos;h&apos; with &apos;s&apos; System.out.println(rs); rs = rs.replace(&apos;s&apos;,&apos;h&apos;); // Replace &apos;s&apos; with &apos;h&apos; System.out.println(rs); } }

Изход:

oooooo-ssss-oooooo oooooo-hhhh-oooooo 

Java String replace() Метод Пример 4

Методът replace() хвърля NullPointerException, когато заместването или целта е нула. Следващият пример потвърждава същото.

метод на подниз в java

Име на файл: ЗаменетеExample4.java

 public class ReplaceExample4 { // main method public static void main(String argvs[]) { String str = &apos;For learning Java, JavaTpoint is a very good site.&apos;; int size = str.length(); System.out.println(str); String target = null; // replacing null with JavaTpoint. Hence, the NullPointerException is raised. str = str.replace(target, &apos;JavaTpoint &apos;); System.out.println(str); } } 

Изход:

 For learning Java, JavaTpoint is a very good site. Exception in thread &apos;main&apos; java.lang.NullPointerException at java.base/java.lang.String.replace(String.java:2142) at ReplaceExample4.main(ReplaceExample4.java:12)