AP CSA String Manipulation and 2D Arrays

Question 1

Which method returns the number of characters in a String in Java?

Accepted Answer

length()

Answer

size()

Answer

count()

Answer

charAt()

Question 2

What does `str.substring(2, 5)` return for `str = "ABCDEFG"`?

Accepted Answer

"CDE"

Answer

"BCD"

Answer

"CDEF"

Answer

"BCDE"

Question 3

What does `str.charAt(0)` return for `str = "Hello"`?

Accepted Answer

'H'

Answer

'e'

Answer

"H"

Answer

0

Question 4

How do you compare two Strings for equal content in Java?

Accepted Answer

str1.equals(str2)

Answer

str1 == str2

Answer

str1.compareTo(str2) == 0 (also valid but equals is standard)

Answer

str1.equalsTo(str2)

Question 5

What does `str.indexOf("lo")` return for `str = "Hello"`?

Accepted Answer

3

Answer

2

Answer

0

Answer

-1

Question 6

What is the result of `"Hello" + " " + "World"`?

Accepted Answer

"Hello World"

Answer

"HelloWorld"

Answer

A compile error

Answer

"Hello" " " "World"