Please explain the power and the use of exlamation "!" in javascript programming

[kingot]

Hi,
Please i am confuse to know the work of this sign (!)...which is exclamation sign in programming.

i have this code here which which i remove the exclamation sign (!)..it dont work but when i add it ,then it work.

Here is the code
<script type="text/javascript">
function getvalue()
{
var mytextfield=document.getElementById("mytext");
if(mytextfield.value!="")
{
alert("You Entered:"+mytextfield.value)
}
else{
alert("would you enter some text")
}
}
</script>
<input type="text" id="mytext" size="30">
<input type="button" value="check" onclick="getvalue()">

Please help me to understand the use of this sign !.

Thank you.
Clement Osei.

[TheGAME1264]

In conjunction with the equals sign, it means "not equal to".

[kingot]

HI Thegame,

Thanks.But can you have time to mentor me.I need you to make me know better about web development.

Clement Osei.

[TheGAME1264]

I don't really "mentor" people as such. I just try to guide them to a point where they can answer their own questions and take something I've told them and do their own thing with it. That's innovation.

[kingot]

Hi,
Thanks.But how can you help me apart from this forum discussion.
Because i want to become a fully web developer.

Thanks.
Clement Osei

[RiDunne]

I would suggest using everyone's best friend, Google, and following some beginner tutorials.

[TheGAME1264]

The question I have is, "why would I help you outside of the forums?" You get to become a web developer if I help you (possibly). What's in it for me in return?

It doesn't really matter, though. I don't have that kind of time, and I'd rather help people in an environment where others can learn besides those who post.