how to get a float using parseFloat(0.00) - javascript

How can I get a float of 0.00. The reason I need 0.00, is because I am going to be accumalating float values by adding. Hence starting with 0.00.
I tried
var tmp ='0.00'
tmp = parseFloat(tmp.toString()).toFixed(2);
totals = parseFloat(tmp)
tmp is 0.00 but totals is 0. How can I make total 0.00? I need it to stay as a float and not a string.
Thanks

You can use the string tmp variable and then when you need to add to it use:
tmp = (+tmp + 8).toFixed(2);
JSFIDDLE DEMO
Or simply write a function to do that seeing that you'll have to do that many times:
function strAdd( tmp, num ) {
return (+tmp + num).toFixed(2);
}

There is no such thing as an integer type in javascript. There is only Number, which is stored as a double precision floating point. So to get a floating point value with 0.00, you need only to do this:
var tmp = 0;

var tmp ='0.00'
tmp = parseFloat(tmp.toString()).toFixed(2);
totals=parseFloat(tmp).toFixed(2);
alert(totals); //0.00
parseFloat() without toFixed() removes zeros after dot. So you need to add toFixed() again.

Here is dynamic floatParser for those who need
function customParseFloat(number){
if(isNaN(parseFloat(number)) === false){
let toFixedLength = 0;
let str = String(number);
// You may add/remove seperator according to your needs
[".", ","].forEach(seperator=>{
let arr = str.split(seperator);
if( arr.length === 2 ){
toFixedLength = arr[1].length;
}
})
return parseFloat(str).toFixed(toFixedLength);
}
return number; // Not a number, so you may throw exception or return number itself
}

You can use parseFloat function in Javascript.
<button onclick="myFunction()">Try it</button>
<p id="demo"></p>
<script>
function myFunction() {
var a = parseFloat("10") + "<br>";
var b = parseFloat("10.00") + "<br>";
var c = parseFloat("10.33") + "<br>";
var d = parseFloat("34 45 66") + "<br>";
var e = parseFloat(" 60 ") + "<br>";
var f = parseFloat("40 years") + "<br>";
var g = parseFloat("He was 40") + "<br>";
var n = a + b + c + d + e + f + g;
document.getElementById("demo").innerHTML = n;
}
</script>

Related

Javascript median using for

So I'm trying to learn javascript, and I want to find the median of some numbers that I insert into a prompt when I click on the button "find median".
function Media()
{
var n = prompt("number of elements?");
var i = 1;
var s = 0;
for (i=1;i<=n;i++)
{
var m = prompt("insert # " +i);
s = s+m;
}
var media = s/n;
document.getElementById("rezultat").innerHTML = "result: " +media
}
I made a test with two numbers, 1 and 2, and the median was 6, and i cant figure what i've done wrong
You should parse the result of prompt to an integer;
How to convert a string to an integer in JavaScript?
function Media() {
var n = parseInt(prompt("number of elements?"));
var i = 1;
var s = 0;
for (i=1;i<=n;i++)
{
var m = prompt("insert # " +i);
m = parseInt(m);
s = s+m;
}
var media = s/n;
document.getElementById("rezultat").innerHTML = "result: " +media
}
Media();
<div id='rezultat' />
You should also parse the result of prompt using parseInt
var m = parseInt(prompt("insert # " + i));
s/n gives the mean of the input. If you are looking for the median, you should use an array to store the inputs and get the element(s) in the middle.

Evaluation for all purposes JavaScript

I want an eval() function which will calculate brackets as same as normal calculations but here is my code
var str = "2(3)+2(5)+7(2)+2"
var w = 0;
var output = str.split("").map(function(v, i) {
var x = ""
var m = v.indexOf("(")
if (m == 0) {
x += str[i - 1] * str[i + 1]
}
return x;
}).join("")
console.log(eval(output))
Which takes the string str as input but outputs 61014 and whenever I try evaluating the output string, it remains same.
Obligatory "eval() is evil"
In this case, you can probably parse the input. Something like...
var str = "2(3)+2(5)+7(2)+2";
var out = str.replace(/(\d+)\((\d+)\)/g,(_,a,b)=>+a*b);
console.log(out);
while( out.indexOf("+") > -1) {
out = out.replace(/(\d+)\+(\d+)/g,(_,a,b)=>+a+(+b));
}
console.log(out);
You can do it much simplier, just insert '*' in a right positions before brackets
var str = "2(3)+2(5)+7(2)+2"
var output = str.replace(/\d\(/g, v => v[0] + '*' + v[1])
console.log(eval(output))

Adding a comma at every third number character

In my code I have a variable myCash, which is printed into an h1 element using javaScript's innerHTML. I found a function online that puts a comma after every third character from the end of the number so that the number is easier to read. I've tried for a couple of hours now sending my variable myCash into the function and then print it on the screen. I CANNOT get it to work.
I've tried just alerting the new variable to the screen after page load or by pressing a button, but I get nothing and the alert doesn't even work. Here's the comma insert function:
function commaFormatted(amount) {
var delimiter = ","; // replace comma if desired
amount = new String(amount);
var a = amount.split('.',2)
var d = a[1];
var i = parseInt(a[0]);
if(isNaN(i)) { return ''; }
var minus = '';
if(i < 0) { minus = '-'; }
i = Math.abs(i);
var n = new String(i);
var a = [];
while(n.length > 3)
{
var nn = n.substr(n.length-3);
a.unshift(nn);
n = n.substr(0,n.length-3);
}
if(n.length > 0) { a.unshift(n); }
n = a.join(delimiter);
if(d.length < 1) { amount = n; }
else { amount = n + '.' + d; }
amount = minus + amount;
return amount;
}
now when I want my variable to change I've tried it a few different ways including this:
var newMyCash = commaFormatted(myCash);
alert(newMyCash);
and this:
alert(commaFormatted(myCash);
Where of course myCash equal some large number;
This does absolutely nothing! What am I doing wrong here??
Also,
Try this as a drop in replacement and try alerting the response:
http://phpjs.org/functions/number_format:481
Do you see any errors in the console of your browser (usually f12)?
This is not my function, but I hope it helps you.
function addCommas(nStr)
{
nStr += '';
x = nStr.split('.');
x1 = x[0];
x2 = x.length > 1 ? '.' + x[1] : '';
var rgx = /(\d+)(\d{3})/;
while (rgx.test(x1)) {
x1 = x1.replace(rgx, '$1' + ',' + '$2');
}
return x1 + x2;
}
Usage:
var newMyCash = addCommas( myCash ); alert( newMyCash );
Source: http://www.mredkj.com/javascript/nfbasic.html
You are most likely not passing in a number that contains a decimal, which the function expects.
Working Demo

Unicode value \uXXXX to Character in Javascript

I've never done this before and am not sure why it's outputting the infamous � encoding character. Any ideas on how to output characters as they should (ASCII+Unicode)? I think \u0041-\u005A should print A-Z in UTF-8, which Firefox is reporting is the page encoding.
var c = new Array("F","E","D","C","B","A",9,8,7,6,5,4,3,2,1,0);
var n = 0;
var d = "";
var o = "";
for (var i=16;i--;){
for (var j=16;j--;){
for (var k=16;k--;){
for (var l=16;l--;){
d = c[i].toString()
+ c[j].toString()
+ c[k].toString()
+ c[l].toString();
o += ( ++n + ": "
+ d + " = "
+ String.fromCharCode("\\u" + d)
+ "\n<br />" );
if(n>=500){i=j=k=l=0;} // stop early
}
}
}
}
document.write(o);
The .fromCharCode() function takes a number, not a string. You can't put together a string like that and expect the parser to do what you think it'll do; that's just not the way the language works.
You could ammend your code to make a string (without the '\u') from your hex number, and call
var n = parseInt(hexString, 16);
to get the value. Then you could call .fromCharCode() with that value.
A useful snippet for replacing all unicode-encoded special characters in a text is:
var rawText = unicodeEncodedText.replace(
/\\u([0-9a-f]{4})/g,
function (whole, group1) {
return String.fromCharCode(parseInt(group1, 16));
}
);
Using replace, fromCharCode and parseInt
If you want to use the \unnnn syntax to create characters, you have to do that in a literal string in the code. If you want to do it dynamically, you have to do it in a literal string that is evaluated at runtime:
var hex = "0123456789ABCDEF";
var s = "";
for (var i = 65; i <= 90; i++) {
var hi = i >> 4;
var lo = i % 16;
var code = "'\\u00" + hex[hi] + hex[lo] + "'";
var char = eval(code);
s += char;
}
document.write(s);
Of course, just using String.fromCharCode(i) would be a lot easier...

How do I convert an integer to decimal in JavaScript?

I have a number in JavaScript that I'd like to convert to a money format:
556633 -> £5566.33
How do I do this in JavaScript?
Try this:
var num = 10;
var result = num.toFixed(2); // result will equal string "10.00"
This works:
var currencyString = "£" + (amount/100).toFixed(2);
Try
"£"+556633/100
This script making only integer to decimal.
Seperate the thousands
onclick='alert(MakeDecimal(123456789));'
function MakeDecimal(Number) {
Number = Number + "" // Convert Number to string if not
Number = Number.split('').reverse().join(''); //Reverse string
var Result = "";
for (i = 0; i <= Number.length; i += 3) {
Result = Result + Number.substring(i, i + 3) + ".";
}
Result = Result.split('').reverse().join(''); //Reverse again
if (!isFinite(Result.substring(0, 1))) Result = Result.substring(1, Result.length); // Remove first dot, if have.
if (!isFinite(Result.substring(0, 1))) Result = Result.substring(1, Result.length); // Remove first dot, if have.
return Result;
}
Using template literals you can achieve this:
const num = 556633;
const formattedNum = `${num/100}.00`;
console.log(formattedNum);

Categories