I have to write a calculator in HTML. I really can't find what is going wrong and it does not show the results. I can't find something wrong can you help? I'm running it in Chrome.
JavaScript File and and the HTML:
showresult(choise){
var n1=parsefloat(document.getElementById('num1').value);
var n2=parsefloat(document.getElementById('num2').value);
var r;
var c=choise;
switch(c)
{
case '1':
r=n1+n2;
break;
case '2':
r=n1-n2;
break;
case '3':
r=n1*n2;
break;
case '4':
r=n1/n2;
break;
case '5':
r=n2*100/n1;
break;
default:
break;
}
document.getElementById('result').innerHTML=r;
}<!DOCTYPE html>
<html>
<head>
<title>Calculator</title>
<script src="calculator.js" type="text/javascript"></script>
</head>
<body>
<h1>My calculator</h1>
<table border="1" cellpadding="5" cellspacing="5" width="600">
<tr align="center">
<td>First number</td>
<td>Second Number</td>
<td>Result</td>
</tr>
<tr align="center">
<td><input name="number1" type="text" size=10 id='num1'/></td>
<td><input name="number2" type="text" size=10 id='num2'/></td>
<td> <input type="text" id='result' readonly ></td>
</tr>
<tr>
<td colspan="3">
<button onclick="showresult('1')">+</button>
<button onclick="showresult('2')">-</button>
<button onclick="showresult('3')">*</button>
<button onclick="showresult('4')">/</button>
<button onclick="showresult('5')">%</button>
</td>
</tr>
</table>
</body>
</html>I have to write a calculator in HTML. I really can't find what is going wrong and it does not show the results. I can't find something wrong can you help? I'm running it in Chrome.
JavaScript File and and the HTML:
showresult(choise){
var n1=parsefloat(document.getElementById('num1').value);
var n2=parsefloat(document.getElementById('num2').value);
var r;
var c=choise;
switch(c)
{
case '1':
r=n1+n2;
break;
case '2':
r=n1-n2;
break;
case '3':
r=n1*n2;
break;
case '4':
r=n1/n2;
break;
case '5':
r=n2*100/n1;
break;
default:
break;
}
document.getElementById('result').innerHTML=r;
}<!DOCTYPE html>
<html>
<head>
<title>Calculator</title>
<script src="calculator.js" type="text/javascript"></script>
</head>
<body>
<h1>My calculator</h1>
<table border="1" cellpadding="5" cellspacing="5" width="600">
<tr align="center">
<td>First number</td>
<td>Second Number</td>
<td>Result</td>
</tr>
<tr align="center">
<td><input name="number1" type="text" size=10 id='num1'/></td>
<td><input name="number2" type="text" size=10 id='num2'/></td>
<td> <input type="text" id='result' readonly ></td>
</tr>
<tr>
<td colspan="3">
<button onclick="showresult('1')">+</button>
<button onclick="showresult('2')">-</button>
<button onclick="showresult('3')">*</button>
<button onclick="showresult('4')">/</button>
<button onclick="showresult('5')">%</button>
</td>
</tr>
</table>
</body>
</html>- Simple calculator on "html" or JS? – Diego Cardenas Commented Nov 24, 2014 at 18:17
- html with a javascript file – valentinosael Commented Nov 24, 2014 at 18:18
8 Answers
Reset to default 6Things to fix:
1) Assign to value, not innerHTML, when referring to an input element. (They have no content, hence no innerHTML.
2) Start a function declaration with the keyword function.
3) It’s parseFloat, not parsefloat. JavaScript is case-sensitive.
Minimally fixed code:
function showresult(choise){
var n1=parseFloat(document.getElementById('num1').value);
var n2=parseFloat(document.getElementById('num2').value);
var r;
var c=choise;
switch(c)
{
case '1':
r=n1+n2;
break;
case '2':
r=n1-n2;
break;
case '3':
r=n1*n2;
break;
case '4':
r=n1/n2;
break;
case '5':
r=n2*100/n1;
break;
default:
break;
}
document.getElementById('result').value=r;
}<!DOCTYPE html>
<html>
<head>
<title>Calculator</title>
<script src="calculator.js" type="text/javascript"></script>
</head>
<body>
<h1>My calculator</h1>
<table border="1" cellpadding="5" cellspacing="5" width="600">
<tr align="center">
<td>First number</td>
<td>Second Number</td>
<td>Result</td>
</tr>
<tr align="center">
<td><input name="number1" type="text" size=10 id='num1'/></td>
<td><input name="number2" type="text" size=10 id='num2'/></td>
<td> <input type="text" id='result' readonly ></td>
</tr>
<tr>
<td colspan="3">
<button onclick="showresult('1')">+</button>
<button onclick="showresult('2')">-</button>
<button onclick="showresult('3')">*</button>
<button onclick="showresult('4')">/</button>
<button onclick="showresult('5')">%</button>
</td>
</tr>
</table>
</body>
</html>You are setting the innerHTML property of an input, which doesn't work
because inputs have value property, if you want to show text/data in them.
you should change this line:
document.getElementById('result').innerHTML=r;
to:
document.getElementById('result').value = r;
on creating a calculator in simple javascript, also check this tutorial out that i wrote, it may help you: Create a calulator in javascript - Tutorial by 10code.dev
var cnum = document.getElementsByClassName('c-num')[0];
var cope = document.getElementsByClassName('c-operator')[0];
var intom = document.getElementById('intop');
var inbottom = document.getElementById('inbottom');
var newinbottom;
var newinbottom2;
var sign;
for(i=0;i<10;i++){
cnum.innerHTML +='<span class="numb" value="'+i+'" id="numid'+i+'" onclick="puton('+i+')">'+i+'</span>';
}
document.getElementById('numid0').style.order = "1";
function puton(numb){
inbottom.value += numb
}
function ans(answer){
//console.log(sign)
if(inbottom.value ==''){
alert('type input');
}else if(sign == "plus"){
newinbottom2 = inbottom.value;
intom.value = inbottom.value;
inbottom.value = parseInt(newinbottom) + parseInt(newinbottom2);
}else if(sign == "minus"){
newinbottom2 = inbottom.value;
intom.value = inbottom.value;
inbottom.value = newinbottom - newinbottom2;
}else if(sign == "divi"){
newinbottom2 = inbottom.value;
intom.value = inbottom.value;
inbottom.value = newinbottom / newinbottom2;
}else if(sign == "mul"){
newinbottom2 = inbottom.value;
intom.value = inbottom.value;
inbottom.value = newinbottom * newinbottom2;
}
sign ='';
}
function opr(opra){
if(sign != '' && sign != undefined){
ans();
}
else if(opra == "clr"){
intom.value =''
inbottom.value ='';
newinbottom='';
newinbottom='';
sign ='';
}
else if(opra == "plus"){
newinbottom = inbottom.value;
intom.value = inbottom.value;
inbottom.value = '';
sign = "plus";
}else if(opra == "minus"){
newinbottom = inbottom.value;
intom.value = inbottom.value;
inbottom.value = '';
sign = "minus";
}else if(opra == "divi"){
newinbottom = inbottom.value;
intom.value = inbottom.value;
inbottom.value = '';
sign = "divi";
}else if(opra == "mul"){
newinbottom = inbottom.value;
intom.value = inbottom.value;
inbottom.value = '';
sign = "mul";
}
}
.main{
width:100vw;
height: 100vh;
display: flex;
justify-content: center;
}
.c-body {
width: 400px;
height: 255px;
background: #ccc;
border: 1px solid;
}
.c-num{
width: 100%;
display: flex;
flex-wrap: wrap;
}
.c-operator{
flex-shrink: 1;
display: flex;
flex-wrap: wrap;
flex-direction: column;
}
.c-row{
display: flex;
flex-flow: row;
}
.c-operator [id^='numid']{
width: 90px;
flex-direction: initial;
}
[id^='numid'] {
display: flex;
flex-shrink: 1;
background: #fff;
padding: 4px;
margin: 4px;
width: 80px;
justify-content: center;
cursor: pointer;
flex-direction: inherit;
}
.c-minputs .inbox{
display: block;
width: 100%;
}
[id^='numid']:hover{
background: #f5f5f5;
}<div class="main">
<div class="c-body">
<div class="c-minputs">
<input id="intop" type="number" class="topin inbox" disabled>
<input id="inbottom" type="number" class="bottomin inbox" placeholder="Type Here">
</div>
<div class="c-row">
<div class="c-num">
</div>
<div class="c-operator">
<span class="numb" id="numidplus" onclick="opr('plus')">+</span>
<span class="numb" id="numidminus" onclick="opr('minus')">-</span>
<span class="numb" id="numiddiv" onclick="opr('divi')">/</span>
<span class="numb" id="numidmul" onclick="opr('mul')">*</span>
<span class="numb" id="numidans" onclick="ans('answer')">=</span>
<span class="numb" id="numidclr" onclick="opr('clr')">c</span>
</div>
</div>
</div>
</div>Make sure you declare the function correctly.
function showresult(choise) {
/* ... */
}
Also, remember that Javascript is case sensitive therefore the right way to parse a float is
parseFloat()
Lastly, as pointed out by gillesc, use the attribute value on the input element.
document.getElementById('result').value=r;
you should replace "innerHTML" to "value" in your code.
If you want to access the text within a non-input HTML element, then you are going to have to use the innerHTML property instead of value
Now code bees:
document.getElementById('result').value=r;
Here we used the value property that all input elements have to use to grab the value the user enters.
You can use this in your code
function calc(form) {
var D = "0";
var A = document.getElementById("num1").value;
var B = document.getElementById("op").value;
var C = document.getElementById("num2").value;
switch(B){
case'+':
D= parseInt(A)+parseInt(C); break;
case'-':
D= parseInt(A)-parseInt(C); break;
case'*':
D=parseInt(A)*parseInt(C); break;
case'/':
D=parseInt(A)/parseInt(C); break;
}
}
<script>
var num1;
var op;
function pressBtn(value){
var prev = document.forms["calc"]["display"].value;
if (!(prev == "" && value==0)){
var newval = prev+value;
document.forms["calc"]["display"].value = newval;
}
}
function pressOP(operator){
op = operator;
var display = document.forms["calc"]["display"].value;
num1 = parseInt(display);
document.forms["calc"]["display"].value = "";
}
function pressEq(){
var display = document.forms["calc"]["display"].value;
var num2 = parseInt(display);
switch(op){
case "P":
var ans=num1+num2;
break;
case "M":
var ans=num1-num2;
break;
}
document.forms["calc"]["display"].value = ans;
}
</script><style>
input[type=button]{
width: 100px;
height: 100px;
font-size: 36px;
margin: 5px;
}
input[type=text]{
width: 300px;
height: 75px;
font-size: 48px;
margin: 5px;
text-align: right;
}
</style><body style="background: #ccc;">
<div style="width: 500px; margin: auto; background: #fff; text-align: center">
<form name="calc">
<input type="text" name="display" readonly ><br>
<input type="button" name="btn7" value="7" onClick="pressBtn(7)">
<input type="button" name="btn8" value="8" onClick="pressBtn(8)">
<input type="button" name="btn9" value="9" onClick="pressBtn(9)"><br>
<input type="button" name="btn4" value="4" onClick="pressBtn(4)">
<input type="button" name="btn5" value="5" onClick="pressBtn(5)">
<input type="button" name="btn6" value="6" onClick="pressBtn(6)"><br>
<input type="button" name="btn1" value="1" onClick="pressBtn(1)">
<input type="button" name="btn2" value="2" onClick="pressBtn(2)">
<input type="button" name="btn3" value="3" onClick="pressBtn(3)"><br>
<input type="button" name="btn0" value="0" onClick="pressBtn(0)">
<input type="button" name="btnPlus" value="+" onClick="pressOP('P')" >
<input type="button" name="btnPlus" value="-" onClick="pressOP('M')" ><br>
<input type="button" name="btnEq" value="=" onClick="pressEq();" >
</form>
</div>
</body><!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>stackoverflow</title>
<style>
body{
background: linear-gradient(90deg, rgba(2,0,36,1) 0%, rgba(9,9,121,1) 35%, rgba(0,212,255,1) 100%);
}
.button {
box-shadow: 0px 10px 14px -7px #276873;
background: linear-gradient(to bottom, #599bb3 5%, #408c99 100%);
background-color: #599bb3;
border-radius: 4px;
border: 1px solid #29668f;
display: inline-block;
cursor: pointer;
color: #ffffff;
font-family: Arial;
font-size: 25px;
font-weight: bold;
padding: 21px 6px;
text-decoration: none;
text-shadow: 0px 1px 0px #3d768a;
height: 50px;
width: 80px;
padding: 0px;
}
.button:hover {
background:linear-gradient(to bottom, #408c99 5%, #599bb3 100%);
background-color:#408c99;
}
form>input{
height: 40px;
width: 329px;
border-radius: 4px;
border: none;
margin-left: 500px;
font-size: 30px;
}
table{
margin-left: 500px;
}
</style>
</head>
<body>
<div id="main">
<form name="form">
<input name="textview">
</form>
<table>
<tr>
<td><input type="button" class="button" value="Clear" onClick="c()"></td>
</tr>
<tr>
<td><input type="button" class="button" value="7" onClick="insert(7)"></td>
<td><input type="button" class="button" value="8" onClick="insert(8)"></td>
<td><input type="button" class="button" value="9" onClick="insert(9)"></td>
<td><input type="button" class="button" value="/" onClick="insert('/')"></td>
</tr>
<tr>
<td><input type="button" class="button" value="4" onClick="insert(4)"></td>
<td><input type="button" class="button" value="5" onClick="insert(5)"></td>
<td><input type="button" class="button" value="6" onClick="insert(6)"></td>
<td><input type="button" class="button" value="-" onClick="insert('-')"></td>
</tr>
<tr>
<td><input type="button" class="button" value="1" onClick="insert(1)"></td>
<td><input type="button" class="button" value="2" onClick="insert(2)"></td>
<td><input type="button" class="button" value="3" onClick="insert(3)"></td>
<td><input type="button" class="button" value="+" onClick="insert('+')"></td>
</tr>
<tr>
<td><input type="button" class="button" value="0" onClick="insert(0)"></td>
<td><input type="button" class="button" value="." onClick="insert('.')"></td>
<td><input type="button" class="button" value="=" onClick="equal('=')"></td>
<td><input type="button" class="button" value="*" onClick="insert('*')"></td>
</tr>
</table>
</div>
<script>
function insert(num){
document.form.textview.value = document.form.textview.value+num;
}
function equal(){
let exp = document.form.textview.value;
if(exp){
document.form.textview.value = eval(exp)
}
else{
console.log('Something Wrong')
}
}
function c(){
document.form.textview.value = null;
}
</script>
</body>
</html>