Javascript Learning Data Type

 

JavaScript provides different data types to hold different types of values. There are two types of data types in JavaScript.

The typeof operator is used to get the data type (returns a string) of its operand. The operand can be either a literal or a data structure such as a variable, a function , or an object.

• Primitive Data Type
• Reference Data Type (Non Primitive)

1. Primitive Data Type

• String
• Number
• Boolean
• Null
• Undefined
• Symbol

// Primitive data type
            //String
        let myName = 'Pradeep';
        console.log( 'My String is '+ myName);
        console.log( 'My DataType is '+ (typeOf myName));
        // Output: My String is Pradeep
        // Output: My DataType is string

            // Numbers
        let marks = 45;
        console.log( 'My marks is '+ marks);
        console.log( 'My DataType is '+ (typeof marks));
        // Output: My marks is 45
        // Output: My DataType is Number

            // Boolean
        let isDriver = true;
        console.log('DataType is ' + (typeof isDriver));
        // Output: My DataType is Boolean

            // Null
        let nulVar = null;
        console.log('DataType is ' + (typeof nulVar));
        // Output: My DataType is Object but it's primitive data type 

            // Undefined
        let unDef = undefined;
        console.log('DataType is ' + (typeof unDef));
        // Output: My DataType is Undefined

2. Reference data type

• Array
• Object Literal
• Function
• Dates

 // Refrence data type
            // Arrays
            myarr = [1, 2, 3, 4];
            console.log('DataType is ' + (typeof myarr));

            // Object Literals
            let stMarks{
                pradeep:52,
                Kevu:65,
                Ashwat: 63
            } 
            console.log(stMarks) 
            console.log( 'My DataType is '+ (typeof stMarks)); 
            
            // Function 
            function test(){

            }
            console.log(typeof test)

            // date
            let date = new Date();
            console.log(typeof date)