Questions: Given the following method, what method call will return true? ``` public static boolean isValid(String input) boolean valid = true; if (input. length() != 11) valid = false; else if (input.charAt(3) != ' -' input.charAt(6) != '-') valid = false; else valid = Character.isDigit(input.charAt(0)) Character.isDigit(input.charAt(1)) Character.isDigit(input.charAt(2)) Character.isDigit(input.charAt(4)) Character.isDigit(input.charAt(5)) Character.isDigit(input.charAt(7)) Character.isDigit(input.charAt(8)) Character.isDigit(input.charAt(9)) Character.isDigit(input.charAt(10)); return valid; ``` isValid("123-45-67") isValid("123-456789") isValid("123-45-6789") isValid("ABC-45-6789")

Given the following method, what method call will return true?
```
public static boolean isValid(String input)

boolean valid = true;
if (input. length() != 11)

valid = false;

else

if (input.charAt(3) != ' -' input.charAt(6) != '-')

valid = false;

else

valid =
Character.isDigit(input.charAt(0))
Character.isDigit(input.charAt(1))
Character.isDigit(input.charAt(2))
Character.isDigit(input.charAt(4))
Character.isDigit(input.charAt(5))
Character.isDigit(input.charAt(7))
Character.isDigit(input.charAt(8))
Character.isDigit(input.charAt(9))
Character.isDigit(input.charAt(10));

return valid;

```
isValid("123-45-67")
isValid("123-456789")
isValid("123-45-6789")
isValid("ABC-45-6789")

Transcript text: Given the following method, what method call will return true? ``` public static boolean isValid(String input) { boolean valid = true; if (input. length() != 11) { valid = false; } else { if (input.charAt(3) != ' -' || input.charAt(6) != '-') { valid = false; } else { valid = Character.isDigit(input.charAt(0)) && Character.isDigit(input.charAt(1)) && Character.isDigit(input.charAt(2)) & & Character.isDigit(input.charAt(4)) && Character.isDigit(input.charAt(5)) && Character.isDigit(input.charAt(7)) && Character.isDigit(input.charAt(8)) && Character.isDigit(input.charAt(9)) && Character.isDigit(input.charAt(10)); } } return valid; } ``` isValid("123-45-67") isValid("123-456789") isValid("123-45-6789") isValid("ABC-45-6789")

Solution

Solution Steps

Step 1: Analyze the isValid method

The isValid method checks if an input string represents a valid format. It returns true if the string meets the criteria and false otherwise. The criteria are:

The string must be exactly 11 characters long.
Characters at index 3 and 6 must be hyphens ('-').
All other characters must be digits.

Step 2: Evaluate the given method calls

isValid("123-45-67"): This string satisfies all the conditions (11 characters long, hyphens at correct positions, and digits elsewhere).
isValid("123-456789"): This string fails the length check (11 characters) and the hyphen placement check.
isValid("123-45-6789"): This string fails the length check (11 characters).
isValid("ABC-45-6789"): This string fails because characters at indices 0, 1, and 2 are not digits.