Strings

Question 1

What is a stack?

Answer 1

• Stores local variables
• Stores addresses to objects in the heap
• Follows the last in, last out order

Question 2

What is a heap?

Answer 2

• Stores all objects
• Stores instance variables in objects
• Has a String Pool

Question 3

Two strings store the same message. Is memory used twice?

Answer 3

No. The second string will refer to the first string.

Question 4

What is the difference here?
String str1 = “Hello”;
String str2 = “Hello”;
String str3 = new String(“Hello”);

Answer 4

String str3 will not have the same reference as str1 or str2.

Question 5

What does name.equals(object another) do?

Answer 5

Returns true or false if the strings match

Question 6

What does name.charAt(int index) do?

Answer 6

Returns the character at the index

Question 7

What does name.compareTo(String another) do?

Answer 7

Compares two strings with <, >, and =.

Question 8

How can we use backslashes, quotation marks, line breaks, and tabs within strings?

Answer 8

• \
• "
• \n
• \t

Question 9

Compare the values based on their Unicode index.
a and b
A and a
Cart and Car
Car and Cart

Answer 9

a < b
A < a
Car = Car
Car < Cart

Question 10

How do you convert an int to String?

Answer 10

String.valueOf(int)

Question 11

How do you convert a String to int?

Answer 11

Integer.parseInt(“stringOfNumbers”)

Question 12

What is the format for most math functions?

Answer 12

Math.functionName(neededVariables)