<! DOCTYPE html>
<meta charset= "UTF-8" >
<title></title>
<style>
</style>
<body>
<div>
<input type= "text" size= "ten" id= "Num1"/>
<select name= "sel" id= "sel" >
<option>+</option>
<option>-</option>
<option>*</option>
<option>/</option>
<option>%</option>
</select>
<input type= "text" size= "ten" id= "num2"/>
<button onclick= "Myadd ()" >=</button>
<input type= "text" size= "ten" id= "num3" readonly/>
<div id= "div11" style= "color:red; font-size:12px; ">
</div>
</div>
<script>
function Myadd () {
var div11 = document.getElementById (' div11 ');
var num1 = document.getElementById (' num1 ');
var num2 = document.getElementById (' num2 ');
var num3 = document.getElementById (' num3 ');
var sel = document.getElementById (' sel ');
div11.innerhtml = "";
if (num1.value== "" | | isNaN (num1.value) | | num2.value== "" | | IsNaN (num2.value)) {
div11.innerhtml = ' input content is not a number ';
}else{
if (sel.value== ' + ') {
Num3.value = (parsefloat (num1.value) + parsefloat (num2.value)). toFixed (2);
}else if (sel.value== '-') {
Num3.value = (parsefloat (num1.value)-parsefloat (Num2.value)). toFixed (2);
}else if (sel.value== ' * ') {
Num3.value = (parsefloat (num1.value) * parsefloat (Num2.value)). toFixed (2);
}else if (sel.value== '/') {
if (parsefloat (num2.value) ==0) {
div11.innerhtml = ' dividend cannot be 0 ';
}else{
Num3.value = (parsefloat (num1.value)/parsefloat (Num2.value)). toFixed (2);
}
}else if (sel.value== '% ') {
if (parsefloat (num2.value) ==0) {
div11.innerhtml = ' dividend cannot be 0 ';
}else{
Num3.value = (parsefloat (num1.value)% parsefloat (num2.value)). toFixed (2);
}
}
}
}
</script>
</body>
Subtraction with JavaScript