STRING METHODS & STRING BUILDER

 public class first {

public static void main(String[] args) {

String name="Abhi";

System.out.println(name);

// .length()  returns the length of a string

int a=name.length();

System.out.print("length:");

System.out.println(a);

//or

System.out.println(name.length());

// .toLowerCase() converts the string to lower case

System.out.print("name:");

String lcase=name.toLowerCase();

System.out.println(lcase);

//or

System.out.println(name.toLowerCase());

// .toUpperCase() converts the string to upper case

System.out.print("name:");

String ucase=name.toUpperCase();

System.out.println(ucase);

//or

System.out.println(name.toUpperCase());

//.trim() removes the whitespaces

String nontrimmedname="    Abhi  ";

System.out.println(nontrimmedname);

System.out.print("trimmed name:");

System.out.println(nontrimmedname.trim());

//.substring() returns the substring from the given index value

System.out.print("substring:");

System.out.println(name.substring(2));

//.substring(start,end) returns the sub string from the starting index till ending index. Ending index is excluded

System.out.print("substring:");

System.out.println(name.substring(1,3));

//.replace will replace an old character or target with a new one.

System.out.print("string after replacement:");

System.out.println(name.replace('b', 'h'));

System.out.print("string after replacement:");

System.out.println(name.replace("bhi","hhh!"));

//BOOLEAN

//.startsWith("") returns true or false.

System.out.print("the string starts with hg:");

System.out.println(name.startsWith("hg"));

//.endsWith("") returns true or false.

System.out.print("the string ends with i:");

System.out.println(name.endsWith("i"));

//.charAt(index) returns the character at the given index position

System.out.print("character at 3 index:");

System.out.println(name.charAt(3));

//.indexOf("") reutrns the index of the character or string from where it starts

System.out.print("index of b:");

System.out.println(name.indexOf("b"));

System.out.print("index of hi:");

System.out.println(name.indexOf("hi"));

//.indexOf("",start searching from) it searches from the given index and returns the index of the character and returns -1 if it doesnot match

String modifiedName="abhiabhiabhi";

System.out.print("Index of a in modified name:(start searching from 5");

System.out.println(modifiedName.indexOf("a",5));

System.out.print("index of x:)");

System.out.println(modifiedName.indexOf("x",5));

//.LastIndexOf()  it searches the character from the end and returns the index of the character or string

System.out.print("last index of 'b':");

System.out.println(modifiedName.lastIndexOf("b"));

//.LastIndexOf("",index)  it searches the character from the given index value(ending) and returns the index of the character or string

System.out.print("last index of 'b'start searching from 5:");

System.out.println(modifiedName.lastIndexOf("b",5));

//.equals("string") returns true if the string matches and false if it doesn't

System.out.print("Does the string match:");

System.out.println(name.equals("abhi"));

//.equalsIgnoreCase("string") it ignores the case (either upper or lower)returns true if the string matches and false if it doesn't

System.out.print("Does the string match:");

System.out.println(name.equalsIgnoreCase("abhi"));

}

}

AAPNA

package code.mypack;

public class stringaapna {

    public static void main(String[] args) {

       String name="tony";

       String name2="stark";

     if(name.compareTo(name2)==0)

{

    System.out.println("strings are equal");

}

else{

    System.out.println("Strings are not equal" );

}    

}

}

****************************STRING BUILDER***************************************

// STRING BUILDER

        StringBuilder name = new StringBuilder("abhi");

        // .setCharAt

        name.setCharAt(0, 'b');

        System.out.println(name);

        // .insert

        name.insert(0, 'm');

        System.out.println(name);

        // .delete

        name.delete(0, 2);

        System.out.println(name);

        // .append

        name.append("iii");

        System.out.println(name);

************REVERSING A STRING USING STRING BUILDER*************************

package code.mypack;

// REVERSING A STRING  USING STRINGBUILDER

public class reversestr {

    public static void main(String[] args) {

        StringBuilder name = new StringBuilder("abhii");

        for (int i = 0; i < name.length() / 2; i++) {

            int front = i;

            int back = name.length() - 1 - i;

            char frontchar = name.charAt(front);

            char backchar = name.charAt(back);

            name.setCharAt(front, backchar);

            name.setCharAt(back, frontchar);

        }

        System.out.println(name);

    }

}