I want to make a program with JavaScript which adds the digits of a number until the number of digits in the result is 1.
Example:
57 = 5 + 7 = 12 = 1 + 2 = 3.
I have made a program which does half of the job. Here is it
<!DOCTYPE html>
<html>
<head>
<title>Try</title>
<style type="text/css">
</style>
</head>
<body>
<form><input type="text" onkeyup="sumofDigits(this.value)"></input>
</form>
<h1></h1>
<script type="text/javascript">
function sumofDigits(number) {
var num = number.toString();
var sum = 0;
for (var i = 0; i < num.length; i++) {
sum += parseInt(num.charAt(i), 10);
}
document.querySelector('h1').innerHTML = sum;
}
</script>
</body>
</html>
I want to make a program with JavaScript which adds the digits of a number until the number of digits in the result is 1.
Example:
57 = 5 + 7 = 12 = 1 + 2 = 3.
I have made a program which does half of the job. Here is it
<!DOCTYPE html>
<html>
<head>
<title>Try</title>
<style type="text/css">
</style>
</head>
<body>
<form><input type="text" onkeyup="sumofDigits(this.value)"></input>
</form>
<h1></h1>
<script type="text/javascript">
function sumofDigits(number) {
var num = number.toString();
var sum = 0;
for (var i = 0; i < num.length; i++) {
sum += parseInt(num.charAt(i), 10);
}
document.querySelector('h1').innerHTML = sum;
}
</script>
</body>
</html>
- 1 digits of a number and then the digits of the result until the number of digits of result is 1 ? Could not read it.. – Rayon Commented Feb 28, 2016 at 5:34
- Check the question now – user5730434 Commented Feb 28, 2016 at 5:37
4 Answers
Reset to default 7There is no need of string functions here. You can simply arrive the result with help of mod(% operation.
function sumDigits(number) {
document.querySelector('h1').innerHTML = ((number-1)%9+1);
}
This does it.
function sumDigits(number) {
var num = number.toString();
while (num.length != 1) {
var sum = 0;
for (var i = 0; i < num.length; i++) {
sum += parseInt(num.charAt(i), 10);
}
num = sum.toString();
document.querySelector('h1').innerHTML = sum;
}
}
function sumDigits(number) {
var str = number.toString();
var sum = 0;
for (var i = 0; i < str.length; i++) {
sum += parseInt(str.charAt(i), 10);
}
if (sum > 9)
sumDigits(sum);
else
document.querySelector('h1').innerHTML = sum;
}
Try this
<script type="text/javascript">
function sumDigits(number) {
while( number > 9){
var num = number.toString();
var sum = 0;
for (var i = 0; i < num.length; i++) {
sum += parseInt(num.charAt(i), 10);
}
number = sum;
}
document.querySelector('h1').innerHTML = sum;
}
</script>