<U>Given :

STRING s1= "COMPUTER";

String s2= "competition";

System.out.println(s1.compareTo(s2));

System.out.println(s1.charAt(s2.length() - (9)) - s2.charAt(s2.indexOf('m')));

System.out.println(s1.substring(0,4).equalsIgnoreCase(s2.substring(0,4)));

System.out.println(s1.compareToIgnoreCase(s2));

Output :

-32

-32

true

16

Explanation :

s1 = C O M P U T E R

      0  1  2  3 4  5 6 7

Length of s1 = 8

s2 = c o m p e t  i  t   i  o n

       0 1  2 3 4 5 6 7 8  9 10

Length of s2 = 11

System.out.println(s1.compareTo(s2));

s1.compareTo(s2) : This will compare character by character. And also this function is case sensitive.

So, when it will compare first alphabet : C and c

ASCII value of C = 67

ASCII value of c = 99

67 - 99 = -32

So, output is -32.

System.out.println(s1.charAt(s2.length() - (9))-s2.charAt(s2.indexOf('m')));

s2.length() : This will give the length of s2, i.e., 11

11 - 9 = 2

s1.charAt(2) = M

So, from s1.charAt(s2.length() - (9)) ww will GET M.

s2.indexOf('m') = 2

s2.charAt(2) = m

M - m = 77 - 109 = -32

So, output is -32.

System.out.println(s1.substring(0,4).equalsIgnoreCase(s2.substring(0,4));

s1.substring(0,4) = COMP

s2.substring(0,4) = comp

equalsIgnoreCase() : This is not case sensitive

So, COMP = comp = true

So, output is true.

System.out.println(s1.compareToIgnoreCase(s2)); ​

In case of C , c ⇒ 0

O , o ⇒ 0

M , m ⇒ 0

P , p ⇒ 0

U , e ⇒ 16  (compareToIgnoreCase() ignores the difference of upper and lower case.

So, output is 16.