Tutorial Javascript tutorial 2

Merkuri · 10-26-2012, 10:05 AM

I feel very bad today and i don't know how many errors i will have or how bad i will expain it but i hope you will undarstand it if you have problem ask in comments
I hope that you have undarstand part 1 in this part we will cover Functions, If...Else, Switch

Function

A function is a block of code that will be executed when somebody call it, in JavaScript functions are very used

Exaple

Code:
function MyFunction()
{
alert("My first function");
}

On the first line we give a name to the function (MyFunction in the example)
between {} is the body of the function (the code we what to use later[when we call the function]))
And now let's call it

Code:
<body>
<button onlick="MyFunction()">Function</button>
</body>

This code is simple to undarstand i hope you deal with it

Calling function with arguments
When you call a function you can pass along some values to it these values are called arguments or parameters
example

Code:
<body>

<button onclick="myFunction('Anarchy','Forums')">arguments</button>

<script>
function myFunction(name,name1)
{
alert("Welcome " + name + " to " + name1);
}
</script>

</body>

Here we give values to name and name1

Code:
<button onclick="myFunction('Anarchy','Forums')">arguments</button>

and the function work with those 2 arguments you can have 5-10 even 1235135351325 arguments on function

If...Else

if statement - use this statement to execute some code only if a specified condition is true
if...else statement - use this statement to execute some code if the condition is true and another code if the condition is false
if...else if....else statement - use this statement to select one of many blocks of code to be executed
switch statement - use this statement to select one of many blocks of code to be execute

If statment example

Code:
if (time<18, time>13)
{
    alert(Have a nice day);
}

if the times is between 13 and 18 the program will alert (have a nice day)

If...else Statement

Code:
if (time<20)
  {
  alert("Good day");
  }
else
  {
  alert("Good evening");
  }

If its < than 20 it will alert good day if its > than 20 it will alert good evening

If...else if...else Statement

Code:
if (time<10)
{
alert("Good morning");
}
else if (time<20)
{
alert("Good day");
}11
else
{
alert("Good evening");
}

If the time is less than 10:00, you will get a Good morning alert if not but the time is less than 20:00 you will get a Good day alert otherwise you will get a Good evening alert

Switch
We use the switch statement to select one of many blocks of code to be executed

Example

Code:
var day=new Date().getDay();
switch (day)
{
case 0:
x="Today it's Sunday";
break;
case 1:
x="Today it's Monday";
break;
case 2:
x="Today it's Tuesday";
break;
case 3:
x="Today it's Wednesday";
break;
case 4:
x="Today it's Thursday";
break;
case 5:
x="Today it's Friday";
break;
case 6:
x="Today it's Saturday";
break;
}

Display today's weekday-name. Note that Sunday=0, Monday=1, Tuesday=2, etc

Don't forget to write break; afther each case !

Merkuri · 01-19-2013, 09:48 AM

(01-14-2013, 11:16 AM)john001 Wrote: Hey there. Thanks for this great info. I have problems in using switch but now after reading this it will easily solve my problem. Thanks.

It's pleasure for me to hear that.

i0xIllusi0n · 03-10-2013, 04:33 AM

Loving these tutorials, basic syntaxes and everything. I know other languages so I know most of how everything will look, but I don't know Javascript as an overall language. You should write more of these Smile

Tutorial Javascript tutorial 2
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