2.2 String Methods

• Characters in a String can be accessed using indexing
• In the code `String greeting = "Hello"; char firstChar = greeting.charAt(0);`, the variable `firstChar` is assigned the value 'H'
• The `charAt()` method returns a character at a specific index in the string.

  True
• In the code `String str = "Hello World"; boolean isEqual = str.equals("Hello World");`, the variable `isEqual` is assigned the value true
• Calling `“Hello World”.toUpperCase()` returns the string “HELLO WORLD”
• The `length()` method returns the number of characters
• The `substring()` method includes the character at the `endIndex` in the extracted substring

  False
• What is the value of `charAtIndex` after executing `str.charAt(0)` in the example code?

  'H'
• What is the purpose of the `toUpperCase()` method?

  Converts to uppercase
• What is the value of `lowerCaseText` after executing `text.toLowerCase()` in the example code?

  hello world
• The `substring()` method includes the character at the `endIndex`.

  False
• The `indexOf()` method returns the index of the first occurrence of the specified substring
• Strings in Java are immutable.


  True
• The Integer class in Java is immutable.

  False
• Strings in Java are mutable

  False
• The `charAt(int index)` method returns the character at the specified index
• What does the `equals(String other)` method compare in Java strings?

  Case-sensitive equality
• What are the parameters of the `substring()` method in Java?

  beginIndex, endIndex
• Concatenation in Java creates a new string because strings are immutable
• The `concat()` method can be used for method chaining
• What advantage does the `concat()` method offer over the `+` operator in Java?

  Method chaining
• Strings in Java are mutable.

  False
• Strings in Java can be changed after they are created.

  False
• In the code `String str = "Hello World"; int len = str.length();`, the variable `len` is assigned the value 11
• What is the value of `sub` in the code `String str = "Hello World"; String sub = str.substring(0, 5);`?

  "Hello"
• The `toUpperCase()` method converts all characters in a string to lowercase.

  False
• What does the `equalsIgnoreCase()` method do in Java?

  Compares strings case-insensitively
• What is the return value of `str.length()` in the example code?

  11
• The `isEqual` variable is assigned `true` because `str.equals("Hello World")` returns a case-sensitive comparison.


  True
• What is the value of `upperCaseText` after executing `text.toUpperCase()` in the example code?

  HELLO WORLD
• What is the return value of the `length()` method?

  Number of characters
• What is the value of `subtext` after executing `text.substring(0, 5)` in the example code?

  Hello
• What is the value of `lastIndex` after executing `text.lastIndexOf("Hello")` in the example code?

  12
• What is the value of `fullName` after executing `firstName + " " + lastName` in the example code?

  John Doe
• How can characters in a string be accessed in Java?

  Using indexing
• What does the String class in Java represent?

  Sequences of characters
• What does the `length()` method of the String class return?

  Number of characters
• The `substring(int beginIndex, int endIndex)` method includes the character at the `endIndex`

  False
• Match the method with its purpose:

  `toUpperCase()` ↔️ Converts to uppercase

  `toLowerCase()` ↔️ Converts to lowercase
• What does the `indexOf(String str)` method return if the substring is not found?

  -1