Data Types


Data Types are very important concept in any programming language similarly in JavaScript as well. Variables are use to hold different data types according to the requirement.

  • Data Types define's the type of data.
  • According to the type computer read the data.
  • There are various data types like String,Number,Objects etc.
<script>
var a = a + "codesFamily";
document.write(a); 
</script>

JavaScript Dynamic Data Types

JavaScript has a dynamic data types,which means we can hold different types of data according to our requirement at the run time.

<script>
var x;
x = 10;
x = "codesFamily.";
document.write(x); 
</script>

String

String is a special type in JavaScript. String is always around quotes ,either single quotes or double quotes.

<script>
  var name = "codesFamily"; //using Double quotes
  var name = 'codesFamily'; //using Single quotes
</script>

Number

JavaScript number types are commonly used data types compare to other types.

<script>
    var x = 10;
    var y = 20;
    document.write(x);
    document.write(y); 
</script>

Booleans

Boolean types have only two values either true or false;

<script>
    var x = 10;
    var y = 10;
    var z = 5;
    document.write(x == y); // return true
    document.write(' ',x == z); // return false
</script>

Arrays

JavaScript arrays are always write in square brackets and hold multiple values by using a single variable. values are separated by commas(,).

<script>
    var n = [1, 2, 3, 4];
    document.write(n[1]); 
</script>

Objects

javaScript objects store values in the form of key value pairs. We generally write objects inside curly braces { }.

<script>
  var emp = {
    firstName: "coed",
    lastName: "family"
  };
    document.write(emp.firstName + " " + emp.lastName); 
</script>