Introduction
In this trick, we are going to create a calculator. We need to create a basic structure using HTML, style it using CSS and make it work using JavaScript.
Let's Start
Create an HTML Document
<div class="box">
<div class="display"><input type="text" readonly size="18" id="d"></div>
<div class="keys">
<p><input type="button" class="button gray"
value="mrc" onclick='c("Created....................")'>
<input type="button" class="button gray"
value="m-" onclick='c("...............by............")'>
<input type="button" class="button gray" value="
m+" onclick='c(".....................Anoop")'>
<input type="button" class="button pink"
value="/" onclick='v("/")'></p>
<p><input type="button" class="button black"
value="7" onclick='v("7")'><input type="button"
class="button black" value="8" onclick='v("8")'>
<input type="button" class="button black" value="9"
onclick='v("9")'><input type="button"
class="button pink" value="*" onclick='v("*")'></p>
<p><input type="button" class="button black"
value="4" onclick='v("4")'><input type="button"
class="button black" value="5" onclick='v("5")'>
<input type="button" class="button black" value="6"
onclick='v("6")'><input type="button"
class="button pink" value="-" onclick='v("-")'></p>
<p><input type="button" class="button black"
value="1" onclick='v("1")'><input type="button"
class="button black" value="2" onclick='v("2")'>
<input type="button" class="button black" value="3"
onclick='v("3")'><input type="button"
class="button pink" value="+" onclick='v("+")'></p>
<p><input type="button" class="button black"
value="0" onclick='v("0")'><input type="button"
class="button black" value="." onclick='v(".")'>
<input type="button" class="button black" value="C"
onclick='c("")'><input type="button"
class="button orange" value="=" onclick='e()'></p>
</div>
</div>
Here, I created the div
(.box
) which represent the structure of calculator. Inside it, I created two div
tags, one for display (inside this, I added input type="text"
to display the result and set this to read only) and one for Keys. Here, you see some onclick
event about which I will talk later.
Preview (Using the Above Code Calculator looks like below)
Create CSS Stylesheet
body
{
background-color:tan;
}
.box
{
background-color:#3d4543;
height:300px;
width:250px;
border-radius:10px;
position:relative;
top:80px;
left:40%;
}
Here, I set background color for body
and set the height
, width
and border radius
of class box (.box
).
Preview
CSS
.display
{
background-color:#222;
width:220px;
position:relative;
left:15px;
top:20px;
height:40px;
}
.display input
{
position:relative;
left:2px;
top:2px;
height:35px;
color:black;
background-color:#bccd95;
font-size:21px;
text-align:right;
}
Here, I set .display
background-color
, width
, height
and position
. Inside it, we have an input box, I also adjust its height
, width
, color
, background-color
and position
.
Preview
CSS
.keys
{
position:relative;
top:15px;
}
.button
{
width:40px;
height:30px;
border:none;
border-radius:8px;
margin-left:17px;
cursor:pointer;
border-top:2px solid transparent;
}
.button.gray
{
color:white;
background-color:#6f6f6f;
border-bottom:black 2px solid;
border-top:2px #6f6f6f solid;
}
.button.pink
{
color:black;
background-color:#ff4561;
border-bottom:black 2px solid;
}
.button.black
{
color:white;
background-color:303030;
border-bottom:black 2px solid;
border-top:2px 303030 solid;
}
.button.orange
{
color:black;
background-color:FF9933;
border-bottom:black 2px solid;
border-top:2px FF9933 solid;
}
.gray:active
{
border-top:black 2px solid;
border-bottom:2px #6f6f6f solid;
}
.pink:active
{
border-top:black 2px solid;
border-bottom:#ff4561 2px solid;
}
.black:active
{
border-top:black 2px solid;
border-bottom:#303030 2px solid;
}
.orange:active
{
border-top:black 2px solid;
border-bottom:FF9933 2px solid;
}
p
{
line-height:10px;
}
Here, I adjust position
of div
(.keys
). I use Double Class Selector( example: class=button gray
). By the use of this, I set .button width
, height
, border-radius
, cursor
, etc. This helps me in making all my buttons of the same width
, height
, etc. Then I set .button.gray
color, background-color
, etc.
After that, I create :active
(The :active
pseudo selector will match when an element is being pressed down on by the mouse Cursor.) for buttons. The thing I have done here is to change the top border color to black and bottom color to same as button color. This gives button feel of pressing down.
Preview
Finally, we have created a Calculator
but it does not work. Now we have to do scripting for it (using JavaScript).
Create Script (Using JavaScript)
function c(val)
{
document.getElementById("d").value=val;
}
function v(val)
{
document.getElementById("d").value+=val;
}
function e()
{
try
{
c(eval(document.getElementById("d").value))
}
catch(e)
{
c('Error')
}
}
Here, I have created three functions. Function c(val)
is used for clearing the data from the display. When we click on "C
" button, then onclick='c("")'
event runs and searches for c(val)
function and displays the value according to the parameter passed inside it (here, we have not passed any parameter so the input screen appears blank or clear).
Function v(val)
is used for typing numbers as well as mathematical operators.
Function e()
is used for evaluating, i.e., on clicking "=
" button, value inside the Id="d"
is solved.
You can also download the source file for viewing.
Final Preview (Tried and Tested in Chrome)
That's all. Hope you like it.
Thanks!
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