Your Program Uses a Map Structure to Store a Number

question 84

Multiple Choice

Your program uses a Map structure to store a number of user ids and corresponding email addresses. Although each user must have a unique id, two or more users can share the same email address. Select an appropriate expression to complete the method below, which adds a new id and email address to the map only if the id is not already in use. If the id is already in use, an error message is printed. public static void addUserID(Map<String, String> users, String id, String email)
{
String currentEmail = users.get(id) ;
If (___________________)
{
Users.put(id, email) ;
}
Else
{
System.out.println(id + " is already in use.") ;
}
}

• A) currentEmail.equals(email)
• B) !currentEmail.equals(email)
• C) currentEmail == null
• D) currentEmail != null

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Definitions:

Holmes And Rahe

Psychologists who developed a scale to measure stress based on major life events and their impact on an individual's health.

Type B Personality

A personality type characterized by comparatively lower levels of stress, patience, relaxed state, and a laid-back attitude, in contrast to the more stress-prone Type A personality.

Competitiveness

The desire to win or excel in comparison to others, often driving individuals or groups to perform their best.

Hostility

An emotion expressed through anger, aggression, or opposition towards others or oneself.