Java String Methods

What will myString.length() return?

• 27

• 28

• 26

• 29

Answer explanation

myString is 28 characters long

What will myString.indexOf("Sci") return?

• 8

• 9

• 10

• -1

Answer explanation

remember the first character of a String is at index 0

What will myString.indexOf("x") return?

• 15

• 16

• 17

• -1

Answer explanation

indexOf method returns -1 when the actual parameter is not found in the String object referenced before the dot "."

What will myString.substring(12) return?

• e

• ence is awesome!

• This is invalid

• cience is awesome!

Answer explanation

when only one actual parameter called with the substring method, the substring returned starts at the index given through the end of the String

What will myString.substring(10,15) return?

• Scien

• c

• cienc

• cien

Answer explanation

the index of the last character in the substring returned is one character before the second integer given in the method call

[(from, to) -> to index-1]

What will myString.substring( myString.length()-1) return?

• -1

• e

• This is invalid

• !

Answer explanation

length() is always one more than than the last index, so length()-1 is always gives the last character from a String

What will myString.substring( myString.length()) return?

• !

• e!

• This is invalid

• Computer Science is awesome!

Answer explanation

length() will always return an integer one greater than the index of the last character in a String, so using length() for an index will give a value outside the largest index of a String