Javascipt Basic Syntax, (variable,contatinate,negation,datatypes,document.write,alert,getElementById,innerHTML)

gistfile1.txt

    
    Javascript Variable:
    ====================
    1. You can use (A-Z) Capital Letter.
    2. You can use (a-z) Shorthand Letter.
    3. You will use (0-9) Numeric Number.
    4. But, You can not write any numeric number in the frist of variable.
    
    ** Stucture: variable variable_name = variable_data;
    ** E.g     : x = "Hello Bangladesh"
    
    
    // Javascript Concatination
    
    var firstName = 'Humayun';
    var lastName = 'Ahmed';

    document.write('My Name is: '+firstName+ ' ' +lastName); //Concatinate
    
    // Negation Sign

    var x = -10;

    document.write(x);
    document.write(-x);

    // Datatype of Javascript
    
    1. Boolean.
    2. Null.
    3. Undefined.
    4. Number.
    5. String.
    6. Symbol.
    7. Object.

    var x = 5.5;

    document.write(typeof(x));

    // Document Print
    document.write('My First Javascript Practice');

    // Console Print
    console.log('Hello Javascript');

    // Alert Event
    alert('I am Humayun');

    // getElementById in innerHTML
    document.write(document.getElementById('heading').innerHTML);