Java String replace() Method

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This Java method returns a new string resulting from replacing every occurrence of characters with a new characters

Syntax:

public Str replace(char oldC, char newC)
Parameters:

oldCh - old character.

newCh - new character.

target : target sequence of characters

replacement : replacement sequence of characters

Internal implementation

public String replace(char oldChar, char newChar) 
{  
       if (oldChar != newChar) 
{  
           int len = value.length;  
           int i = -1;  
           char[] val = value;   
  
           while (++i < len) 
              {  
               if (val[i] == oldChar) 
              {  
                   break;  
               }  
           }  
           if (i < len) 
              {  
               char buf[] = new char[len];  
               for (int j = 0; j < i; j++) 
               {  
                   buf[j] = val[j];  
               }  
               while (i < len) 
               {  
                   char c = val[i];  
                   buf[i] = (c == oldChar) ? newChar : c;  
                   i++;  
               }  
               return new String(buf, true);  
           }  
       }  
       return this;  
   }


This fucntion returns a string by replacing oldCh with newCh.


public class Test 
{
    public static void main(String args[]) 
   {
        String S1 = new String("the quick fox jumped");
        System.out.println("Original String is ': " + S1);
        System.out.println("String after replacing 'fox' with 'dog': " + S1.replace("fox", "dog"));
        System.out.println("String after replacing all 't' with 'a': " + S1.replace('t', 'a'));

    }
}


Output:

Original String is ': the quick fox jumped
String after replacing 'fox' with 'dog': the quick dog jumped
String after replacing all 't' with 'a': ahe quick fox jumped
Java String replace(char old, char new) method example

public class Test
{  
public static void main(String args[])
{  
String str1="cprogramcoding is a very good website";  
String re=str1.replace('o','a');
System.out.println(re);  
}
}


Output:

cpragramcading is a very gaad website
Java String replace(CharSequence target, CharSequence replacement) method example

public class Test
{  
public static void main(String args[])
{  
String str1="My name is java";  
String re=str1.replace("is","was");
System.out.println(re);  
}
}


Output:

My name was java
Java String replace() Method Example

public class Test 
{  
    public static void main(String[] args) 
   {  
        String str1 = "oooooo-hhhh-oooooo";  
        String str2= str1.replace("h","s");
        System.out.println(str2);  
        str2 = str2.replace("s","h");  
        System.out.println(str2);  
    }  
}


Output:

oooooo-ssss-oooooo
oooooo-hhhh-oooooo



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