class StringPractice { public static void main(String[] args) { String str = "Hello World"; //Declare a string variable System.out.println(str); //Print the string

    System.out.println(str.toUpperCase());
    System.out.println(str); //Print the string in uppercase

    System.out.println(str.toLowerCase()); //Print the string in lowercase

    /*
     * String is immutable in Java.(we cannot modify it)
     * So when we run str.toUpperCase() or str.toLowerCase(), it will not change the original string.
     * It will return a new string in uppercase or lowercase.
     * if we print str it still remains the same "Hello World";
     */

    System.out.println(str.length()); //Print the length of the string

    //Print the first character of the string
    System.out.println(str.charAt(0)); //charAt() method is used to get the character at a specific index of the string

    //Print the last character of the string
    System.out.println(str.charAt(str.length()-1)); //charAt() method is used to get the character at a specific index of the string

    //Print the index of the character 'W' in the string
    System.out.println(str.indexOf('W')); //indexOf() method is used to get the index of a specific character in the string

    //Print the index of the character 'o' in the string
    System.out.println(str.indexOf('s')); //if character is not found in the string, it will return -1

    //Remove leading and trailing spaces from the string
    String str1 = "  Hello World  ";
    System.out.println(str1.trim()); //trim() method is used to do this

    //Remove all spaces from the string
    System.out.println(str1.replace(" ", "$")); //replace("target","replacement") method is used to do this

    //.equals() method
    String str2 = "Hello World";
    String str3 = "Hello World";
    System.out.println(str2.equals(str3)); //equals() method is used to compare two strings

    //Ascii value of a character
    char ch = 'A';
    System.out.println((int)ch); //type casting 
   
    int value = 97;
    char ch1 = (char)value;
    System.out.println(ch1); //converting int to equivalent charcter in ASCII

}

}