Greetings.
This would be of help to you.
Java String api
Have a look at java.lang -> String.

String s;
s.charAt(5);

s.indexOf('K');

String t = s.toUpperCase();

s.replace(h,b);

Ok, the String class is a very important tool in java. Make yourself famaliar with it.
Go to this Weblink to revise some of its properties.
Weblink

Your code should be simliar to this....
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public static void main(String[] args)
{
/*1) Find the 5th caracter in the string " RUSTIN BOND"
2) Find the index of character "K"in string "KANSAS".
3) Convert the string "hello world"to uppercase.
4) Replace character 'h'with 'b'in the string"humble */

String no1 = "RUSTIN BOND";
String no2 = "KANSAS";
String no3 = "hello world";
String no4 = "humble";

//print out the results

//remember java indicies start at 0
System.out.println("\nCurrent String: " + no1);
System.out.println("The 5th character: " + no1.charAt(4));

//remember java indicies start at 0
System.out.println("\nCurrent String: " + no2);
System.out.println("The index of character k: " + (no2.indexOf("K") + 1) );

System.out.println("\nCurrent String: " + no3);
System.out.println("Convert string to uppercase: " + no3.toUpperCase());

System.out.println("\nCurrent String: " + no4);
System.out.println("Replace character h with b: " + no4.replace('h', 'b'));
}
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Hope that helps! Rickste_r