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Quiz

Test your knowledge of JavaScript variables and expressions by answering the following questions.

Questions

1:Which of the following is not a valid JavaScript variable name?
  1. 2names

  2. _first_and_last_names

  3. FirstAndLast

A1: a. 2names is an invalid JavaScript variable name since it begins with a number. The others are valid, although they're probably not ideal choices for names.
2:If the statement var fig=2 appears in a function, which type of variable does it declare?
  1. A global variable

  2. A local variable

  3. A constant variable

A2: b. Since the variable is declared in a function, it is a local variable. The var keyword ensures that a local variable is created.
3:What will be the result of the JavaScript expression 31 + " angry polar bears"?
  1. An error message

  2. 32

  3. “31 angry polar bears”

A3: c. JavaScript converts the whole expression to the string “31 angry polar bears”. (No offense to polar bears, who are seldom angry and rarely seen in groups this large.)


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