نحوه ایجاد ماشین حساب پیشرفته باjavascript
<head>
<script language=”JavaScript”>
function addChar(input, character) {
if(input.value== null || input.value== “0”)
input.value= character
else
input.value += character
}
function cos(form) {
form.display.value= Math.cos(form.display.value);
}
function sin(form) {
form.display.value= Math.sin(form.display.value);
}
function tan(form) {
form.display.value= Math.tan(form.display.value);
}
function sqrt(form) {
form.display.value= Math.sqrt(form.display.value);
}
function ln(form) {
form.display.value= Math.log(form.display.value);
}
function exp(form) {
form.display.value= Math.exp(form.display.value);
}
function deleteChar(input) {
input.value= input.value.substring(0, input.value.length – 1)
}
function changeSign(input) {
if(input.value.substring(0, 1) == “-“)
input.value= input.value.substring(1, input.value.length)
else
input.value= “-” + input.value
}
function compute(form) {
form.display.value= eval(form.display.value)
}
function square(form) {
form.display.value= eval(form.display.value) * eval(form.display.value)
}
function checkNum(str) {
for (var i = 0; i < str.length; i++) {
var ch = str.substring(i, i+1)
if (ch < “0” || ch > “9”) {
if (ch != “/” && ch != “*” && ch != “+” && ch != “-” && ch != “.”
&& ch != “(” && ch!= “)”) {
alert(“invalid entry!”)
return false
}
}
}
return true
}
</SCRIPT>
<style type=”text/css”>
form#calculator,table#calculator td{
margin:0; padding:0
}
input.cal{width:50px !important; text-align:center; border:1px outset #bbb; background:#f5f5f5; height:23px; margin-top:1px}
input.back{width:154px !important; text-align:center; border:1px outset #bbb; background:#f5f5f5; height:23px; margin-top:1px}
input.view{width:246px !important; background:#ffd; border:1px inset #999; height:21px; padding:2px 5px; font:normal 12px verdana }
</style>
</head>
<body>
<form name=”sci-calc”>
<table border=”0″ cellpadding=”0″ cellspacing=”0″ id=”calculator”>
<tr>
<td colspan=”5″ align=”center”><INPUT name=”display” value=”0″ MAXLENGTH=”25″ class=”view”></td>
</tr>
<tr>
<td align=”center”><input type=”button” class=”cal” value=” exp ” onClick=”if (checkNum(this.form.display.value)) { exp(this.form) }”></td>
<td align=”center”><input type=”button” class=”cal” value=” 7 ” onClick=”addChar(this.form.display, ‘7’)”></td>
<td align=”center”><input type=”button” class=”cal” value=” 8 ” onClick=”addChar(this.form.display, ‘8’)”></td>
<td align=”center”><input type=”button” class=”cal” value=” 9 ” onClick=”addChar(this.form.display, ‘9’)”></td>
<td align=”center”><input type=”button” class=”cal” value=” / ” onClick=”addChar(this.form.display, ‘/’)”></td>
</tr>
<tr>
<td align=”center”><input type=”button” class=”cal” value=” ln ” onClick=”if (checkNum(this.form.display.value)) { ln(this.form) }”></td>
<td align=”center”><input type=”button” class=”cal” value=” 4 ” onClick=”addChar(this.form.display, ‘4’)”></td>
<td align=”center”><input type=”button” class=”cal” value=” 5 ” onClick=”addChar(this.form.display, ‘5’)”></td>
<td align=”center”><input type=”button” class=”cal” value=” 6 ” onClick=”addChar(this.form.display, ‘6’)”></td>
<td align=”center”><input type=”button” class=”cal” value=” * ” onClick=”addChar(this.form.display, ‘*’)”></td>
</tr>
<tr>
<td align=”center”><input type=”button” class=”cal” value=” sqrt ” onClick=”if (checkNum(this.form.display.value)) { sqrt(this.form) }”></td>
<td align=”center”><input type=”button” class=”cal” value=” 1 ” onClick=”addChar(this.form.display, ‘1’)”></td>
<td align=”center”><input type=”button” class=”cal” value=” 2 ” onClick=”addChar(this.form.display, ‘2’)”></td>
<td align=”center”><input type=”button” class=”cal” value=” 3 ” onClick=”addChar(this.form.display, ‘3’)”></td>
<td align=”center”><input name=”button” type=”button” class=”cal” onClick=”addChar(this.form.display, ‘-‘)” value=” – “></td>
</tr>
<tr>
<td align=”center”><input type=”button” class=”cal” value=” sq ” onClick=”if (checkNum(this.form.display.value)) { square(this.form) }”></td>
<td align=”center”><input type=”button” class=”cal” value=” 0 ” onClick=”addChar(this.form.display, ‘0’)”></td>
<td align=”center”><input type=”button” class=”cal” value=” . ” onClick=”addChar(this.form.display, ‘.’)”></td>
<td align=”center”><input type=”button” class=”cal” value=” +/- ” onClick=”changeSign(this.form.display)”></td>
<td align=”center”><input type=”button” class=”cal” value=” + ” onClick=”addChar(this.form.display, ‘+’)”></td>
</tr>
<tr>
<td align=”center”><input type=”button” class=”cal” value=” ( ” onClick=”addChar(this.form.display, ‘(‘)”></td>
<td align=”center”><input type=”button” class=”cal” value=”cos” onClick=”if (checkNum(this.form.display.value)) { cos(this.form) }”></td>
<td align=”center”><input type=”button” class=”cal” value=” sin” onClick=”if (checkNum(this.form.display.value)) { sin(this.form) }”></td>
<td align=”center”><input type=”button” class=”cal” value=” tan” onClick=”if (checkNum(this.form.display.value)) { tan(this.form) }”></td>
<td align=”center”><input type=”button” class=”cal” value=” ) ” onClick=”addChar(this.form.display, ‘)’)”></td>
</tr>
<tr>
<td align=”center”><input type=”button” class=”cal” value=”clear” onClick=”this.form.display.value= 0 “></td>
<td align=”center” colspan=”3″><input type=”button” class=”back” value=”backspace” onClick=”deleteChar(this.form.display)”></td>
<td align=”center”><input type=”button” class=”cal” value=”=” name=”enter” onClick=”if (checkNum(this.form.display.value)) { compute(this.form) }”></td>
</tr>
</table>
</form>
</body>
