Starting on WebApps - JavaScript Quick Start

JavaScript is a great language with a lot of rich functionality. However the greatest benefit of JavaScript is that you can get started with very little knowledge of the language. This example gives a brief overview of some of the language features and constructs to allow you to get started.

You can run the example and view the full source here

function run(){
 // Variable declaration. 
 var a = 1;      // Create a number variable
 var b = "hello";    // Create a string variable
 var c = {};      // Create a object variable
 var d = [];      // Create a array variable    
 // Output the results
 log( "Varible Test. " + a ); // Call a function with a parameter 
 log( "Varible Test. " + b ); // Construct the parameter at call time
 log( "Varible Test. " + c );
 log( "Varible Test. " + d );
 
 // If block
 var ifTest;      // Declare a variable with no value
 if( a === 1 ){     // Test for a specific value
  ifTest = true;    // Assign true or false as a boolean to a variable
 } else {
  ifTest = false;
 }
 log( "If Test. " + ifTest );
 if( b.indexOf("bye") > 0 ){  // Test for a string inside a variable string
  ifTest = true;    // Assign true or false as a boolean to a variable
 } else {
  ifTest = false;
 }
 log( "If Test. " + ifTest );
 
 // For loop
 var forMessage = "";
 for( var i=0; i<10; i++){  // Create a variable and loop through 10 iterations
  forMessage = forMessage + i + ","; // Append a string and a number to a string 
 }
 log( "For Test. " + forMessage );
 
 // Create an Object with properties
 var obj = {      // Create a new object 
  forename: "Andy",   // Add a forename property via declaration
  surname: "Monis"   // Add a surname property via declaration
 }    
 obj.age = 36;     // Add an age property via code
 log( "Object Test. Name=" + obj.forename + " " + obj.surname + " Age=" + obj.age );
 
 // Array Test 
 var arr = [ 'Andy' ];   // Create a new array
 arr.push( 'Monis' );   // Add a new element to the array
 arr.push( '180cm' );
 // Join the array elements into a string for display
 var str = arr.join( " " );
 log( "Array Test. " + str );
}