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Im new in javascript and I'm trying to make a simple currency converter, it is working fine when I select "£Pound" "£Pound" or "£Pound" "R$Real" but when I select "R$Real" "R$Real" runs the "Pound" "R$Real" calculation.
I spent hours trying to figure this out (very frustrating).
How to fix it? Is there another way to do it? (also tried using " if " and " else if " same issue). Thanks!
Here`s the HTML:
<label>Amount:</label>
<input type="text" id="amount" />
<label>From:</label>
<select id="select1">
<option value="pound">£ Pound</option>
<option value="real">R$ Real</option>
</select>
<label>To:</label>
<select id="select2">
<option value="pound">£ Pound</option>
<option value="real">R$ Real</option>
</select>
<input type="button" onClick="calculation()" value="calculate" />
<div id="result"></div>
Here`s the JS:
function calculation() {
var amount = document.getElementById('amount').value;
var currency1 = document.getElementById('select1').value;
var currency2 = document.getElementById('select2').value;
switch((currency1)&&(currency2)){
case "pound":
case "pound":
var y = amount * 1;
document.getElementById('result').innerHTML = "£ " + parseFloat(Math.round(y * 100) / 100).toFixed(2);
break
case "pound":
case "real":
var x = currency2 = 3.40;
var y = amount * x;
document.getElementById('result').innerHTML = "R$ " + parseFloat(Math.round(y * 100) / 100).toFixed(2);
break
case "real":
case "real":
var y = amount * 1;
document.getElementById('result').innerHTML = "R$ " + parseFloat(Math.round(y * 100) / 100).toFixed(2);
break
case "real":
case "pound":
var x = currency2 = 3.40;
var y = amount / x;
document.getElementById('result').innerHTML = "£ " + parseFloat(Math.round(y * 100) / 100).toFixed(2);
}}
Im new in javascript and I'm trying to make a simple currency converter, it is working fine when I select "£Pound" "£Pound" or "£Pound" "R$Real" but when I select "R$Real" "R$Real" runs the "Pound" "R$Real" calculation.
I spent hours trying to figure this out (very frustrating).
How to fix it? Is there another way to do it? (also tried using " if " and " else if " same issue). Thanks!
Here`s the HTML:
<label>Amount:</label>
<input type="text" id="amount" />
<label>From:</label>
<select id="select1">
<option value="pound">£ Pound</option>
<option value="real">R$ Real</option>
</select>
<label>To:</label>
<select id="select2">
<option value="pound">£ Pound</option>
<option value="real">R$ Real</option>
</select>
<input type="button" onClick="calculation()" value="calculate" />
<div id="result"></div>
Here`s the JS:
function calculation() {
var amount = document.getElementById('amount').value;
var currency1 = document.getElementById('select1').value;
var currency2 = document.getElementById('select2').value;
switch((currency1)&&(currency2)){
case "pound":
case "pound":
var y = amount * 1;
document.getElementById('result').innerHTML = "£ " + parseFloat(Math.round(y * 100) / 100).toFixed(2);
break
case "pound":
case "real":
var x = currency2 = 3.40;
var y = amount * x;
document.getElementById('result').innerHTML = "R$ " + parseFloat(Math.round(y * 100) / 100).toFixed(2);
break
case "real":
case "real":
var y = amount * 1;
document.getElementById('result').innerHTML = "R$ " + parseFloat(Math.round(y * 100) / 100).toFixed(2);
break
case "real":
case "pound":
var x = currency2 = 3.40;
var y = amount / x;
document.getElementById('result').innerHTML = "£ " + parseFloat(Math.round(y * 100) / 100).toFixed(2);
}}
2 Answers
Reset to default 5To fix your JS do the following:
The issue is that your switch would pute to a single string, and you are using fall-through switch statements, jsFiddle to demonstrate what I mean.
Switch Statement Documentation for JavaScript
function calculation() {
var amount = document.getElementById('amount').value;
var currency1 = document.getElementById('select1').value;
var currency2 = document.getElementById('select2').value;
switch (currency1 + ' ' + currency2) {
case "pound pound":
var y = amount * 1;
document.getElementById('result').innerHTML = "£ " + parseFloat(Math.round(y * 100) / 100).toFixed(2);
break
case "pound real":
var x = currency2 = 3.40;
var y = amount * x;
document.getElementById('result').innerHTML = "R$ " + parseFloat(Math.round(y * 100) / 100).toFixed(2);
break
case "real real":
var y = amount * 1;
document.getElementById('result').innerHTML = "R$ " + parseFloat(Math.round(y * 100) / 100).toFixed(2);
break
case "real pound":
var x = currency2 = 3.40;
var y = amount / x;
document.getElementById('result').innerHTML = "£ " + parseFloat(Math.round(y * 100) / 100).toFixed(2);
}
}
Use the below to display the number and then just put the symbol in front, as this code will add mas and separators in the right spots, including negative.
Format number to currency:
function formatCurrency(num, precision) {
//identify '(123)' as a negative number
if (typeof num == 'string' && num.toString().indexOf('\\(') >= 0) {
num = '-' + num;
}
if (num === '' || (num === '-' && precision === -1)) {
return;
}
// if the number is valid use it, otherwise clean it
if (isNaN(num)) {
// clean number
if (num === '' || (num === '-' && precision === -1)) {
return;
}
if (isNaN(num)) {
num = '0';
}
}
// evalutate number input
var numParts = String(num).split('.');
var isPositive = (num == Math.abs(num));
var hasDecimals = (numParts.length > 1);
var decimals = (hasDecimals ? numParts[1].toString() : '0');
var originalDecimals = decimals;
// format number
num = Math.abs(numParts[0]);
num = isNaN(num) ? 0 : num;
if (precision >= 0) {
decimals = parseFloat('1.' + decimals); // prepend "0."; (IE does NOT round 0.50.toFixed(0) up, but (1+0.50).toFixed(0)-1
decimals = decimals.toFixed(precision); // round
if (decimals.substring(0, 1) == '2') {
num = Number(num) + 1;
}
decimals = decimals.substring(2); // remove "0."
}
num = String(num);
for (var i = 0; i < Math.floor((num.length - (1 + i)) / 3); i++) {
num = num.substring(0, num.length - (4 * i + 3)) + ',' + num.substring(num.length - (4 * i + 3));
}
if ((hasDecimals && precision == -1) || precision > 0) {
num += '.' + decimals;
}
// format symbol/negative
var format = isPositive ? '%s%n' : '(%s%n)';
var money = format.replace(/%s/g, '$');
money = money.replace(/%n/g, num);
return money;
}
console.log(formatCurrency(12002031203120, 2)) <!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" name="viewport" content="width=device-width, initial-scale=1"/>
<style>
body{
background:linear-gradient(3150deg,#7458ff,#a48afc);
background-size: cover;
height: 800px;
display: flex;
align-items: center;
justify-content:center;
}
.col-md-8{
background-color: rgb(183, 170, 170);
padding: 10px 24px;
border-radius: 20px;
width: 490px;
}
.form-group{
width: 100%;
display: flex;
}
input{
width:95%;
color:aliceblue;
height: 40px;
font-size: 1em;
margin: 0.2em 0;
border-radius: 10px;
border: none;
background: #676666;
outline: none;
padding: 0.1em;
}
select{
width: 50%;
height:40px;
font-size: 30px;
cursor: pointer;
background: #039cfb;
outline: none;
color: black;
padding: 0 1em;
border-radius: 10px;
border: none;
}
</style>
</head>
<body>
<div class="col-md-6 well">
<h3 class="text-primary">Javascript - Simple Currency Converter</h3>
<hr style="border-top:1px dotted #ccc;">
<div class="col-md-8">
<h4>Converter</h4>
<hr style="border-top:1px groovy #ccc;"/>
<div class="form-group">
<select onchange="Currency(); Calculate()" class="form-control" id="converter" style="width:30%;">
<option value="Dollar">Dollar</option>
<option value="Pound">Pound</option>
<option value="Euro">Euro</option>
<option value="Yen">Yen</option>
<option value="Yuan">Yuan</option>
</select>
<br />
<input type="number" oninput="Calculate()" class="form-control" id="value1"/>
</div>
<br /><br />
<div class="form-group">
<label>Pak Rupee:</label>
<input type="number" class="form-control" id="value2" disabled="disabled"/>
</div>
</div>
</div>
<script>
function Currency(){
y = document.getElementById("converter").value;
return y;
}
function Calculate(){ y = Currency();
x = document.getElementById("value1").value;
if(x == ""){
document.getElementById("value2").value = "";
}else{
switch(y){
case "Dollar":
document.getElementById("value2").value = x * 215.99;
break;
case "Pound":
document.getElementById("value2").value = x * 72.39;
break;
case "Euro":
document.getElementById("value2").value = x * 63.84;
break;
case "Yen":
document.getElementById("value2").value = x * 0.49;
break;
case "Yuan":
document.getElementById("value2").value = x * 8.20;
break;
}
}
}
</script>
</body>
</html>
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