Week 32: Jan.19-23 Exercises!

Hi!


      We don't  have class in our ICT Class on Monday and Tuesday.  On wednesday, I've  finished my exercise 2 and 3. While on friday, I had finished my exercise 4.  But I did'nt know how to make the exercise 5. I tried my best.
 
      Here are examples.

    Number() converts to a Number, String() converts to a String, Boolean() converts to a Boolean.

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JavaScript Data Types

In JavaScript there are 5 different data types that can contain values:

• string
• number
• boolean
• object
• function

There are 3 types of objects:

• Object
• Date
• Array

And 2 data types that cannot contain values:

• null
• undefined

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The typeof Operator

You can use the typeof operator to find the data type of a JavaScript variable.

Example

typeof "John"                 // Returns string typeof 3.14                   // Returns numbertypeof NaN                    // Returns numbertypeof false                  // Returns booleantypeof [1,2,3,4]              // Returns objecttypeof {name:'John', age:34}  // Returns objecttypeof new Date()             // Returns objecttypeof function () {}         // Returns functiontypeof myCar                  // Returns undefined (if myCar is not declared)typeof null                   // Returns object

Please observe:

• The data type of NaN is number
• The data type of an array is object
• The data type of a date is object
• The data type of null is object
• The data type of an undefined variable is undefined

You cannot use typeof to define if an object is an JavaScript Array or a JavaScript Date.

Taken from http://www.w3schools.com/js/js_type_conversion.asp.

signing off...