IV. Answer parts A,B, and C
4a)
Return true if the letter 'a' occurs in the given String, andfalse otherwise.
containsA(\"abc\") → true
containsA(\"wxyz\") → false
containsA(\"bcaca\") → true
4b)
Return true if the letter 'a' does not occur inthe given String, and false otherwise.
notContainsA(\"abc\") → false
notContainsA(\"wxyz\") → true
notContainsA(\"bcaca\") → false
4c)
Count the number of times a given char occurs in a given rangeof a String parameter (i.e. starting at a given start index, and upto but not including and end index). If end is greater than thelength of the String, then the method should stop looking at theend of the String.
countCharsInRange(\"java\", \"v\", 1, 2) → 0
countCharsInRange(\"java\", \"v\", 0, 2) → 0
countCharsInRange(\"java\", \"v\", 0, 3) → 1
