1Z0-829 Working with Arrays and Collections Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  Declare the method with a type parameter in angle brackets before the return type, then use the type parameter for parameters and return type, then implement the method body using the type parameter, then invoke the method either with explicit type argument or type inference.

  Why this is correct

  This is correct because the type parameter must be declared in the method signature before the return type, then used in the method signature and body, and finally the method is called with appropriate types.

• ✗

  Write the method body first using a specific type, then replace the specific type with a type parameter, then add the type parameter declaration in the method signature, then call the method with the specific type.

  Why it's wrong here

  This is incorrect because generic type parameters must be declared before they are used; you cannot retroactively add a type parameter to an already written method body.

• ✗

  Declare the method with a type parameter after the return type, then use the type parameter in the method body, then call the method with type inference.

  Why it's wrong here

  This is incorrect because the type parameter must be placed in angle brackets before the return type, not after. Placing it after the return type is syntax error.

• ✗

  Use a wildcard (?) in the method signature instead of a type parameter, then implement the method body, then call the method with different types.

  Why it's wrong here

  This is incorrect because wildcards are used for unknown types in method parameters or return types, not for defining a generic method with a named type parameter that can be used in the body.