i do a simple exercise "Write a JavaScript program to compute the sum of the two given integers. If the two values are same, then returns triple their sum".
InnerHTML is ok but it seems that my variables are string and not numbers (if i use parseFloat however it doesn't work).
Example : p161 = 10; p162 = 5; => ris = 105 and not 15
let p16 = document.getElementById("p16");
document.getElementById("button16").addEventListener("click", es);
function es(){
let p161 = document.getElementById("input161").value;
let p162 = document.getElementById("input162").value;
let ris = 0;
if (p161 == p162){
ris = (p161 + p162)*3;
return p16.innerHTML = ris;
} else {
ris = p161 + p162;
return p16.innerHTML = ris;
}
}
You are concatenating strings so what you see makes sense. Since you are looking for the sum of integers I dont see why you need to parseFloat. If you want numbers you should just do
let p161 = +document.getElementById("input161").value;
let p162 = +document.getElementById("input162").value;
Plus sign in this case is the unary operator that will convert value to Number type according to ECMA spec
Related
I am using nerdamer.solve to solve roots but the roots are long and not truncated. I wanted to get truncated values upto 4 decimal places. How can I achieve this?
I am using the following code to solve and display output in html:
var r = nerdamer.solve(`1 - ${a} * x^(${p}) + ${b}`, 'x');
document.getElementById("polesAns").innerHTML= r.toString();
The folllowing is output:
[(138655807/135201312)*i+49385501/48155102,(-138655807/135201312)*i+49385501/48155102,(58886197/57419096)*i-49385501/48155102,(-58886197/57419096)*i-49385501/48155102,-560373381/386371730,172668482/119053157,(145619303/100403024)*i-5753750945848186/10000000000000000000000000000000,(-560373381/386371730)*i-5753750945848186/10000000000000000000000000000000]
There is no division performed also.
I tried the solution posted here:
How to use .toFixed() (or any alternative) on Nerdamer.solve solutions?
But how can I do this with my code? I tried the following:
var value = `1 - ${a} * x^(${p}) + ${b}`;
var toFixed = function(value, n) {
var img = Number(nerdamer.imagpart(value).text()).toFixed(n);
var real = Number(nerdamer.realpart(value).text()).toFixed(n);
// Format the number assuming i denotes imaginary in your case
var formatted = '';
if(real !== '0.0000') {
formatted += real;
}
if(img !== '0.0000') {
// Put the plus sign betweent the real and imaginary
if(img.charAt(0) !== '-' && formatted) {
formatted += '+';
}
// Assuming you're using i and not j for instance
formatted += img+'i';
}
return formatted;
};
sol_raw = this.nerdamer.solve(value,'s');
xs = this.nerdamer(sol_raw.toString()).each(function(solution) {
roundedSolutions.push(toFixed(solution, 4));
});
this.setState({
solution: roundedSolution.join(''),
equation:value})
document.getElementById("polesAns").value = solution.toString();
I don't understand the this.setState() part , should i declare sol_raw and xs as var?
Also the substitution of variable is used in the my above root equation from advice here javascript Solving equation with subsitution of variable value
thank you
how to convert this giant number 7.125693126643573e+26 to pure number in JS without any scientific notation
Chances are, if the number is provided in scientific notation it'll probably be too large to use integers to represent it without integer overflow occurring. Use string functions to break the scientific notation number apart and construct a new string.
const largeNumber = "7.125693126643573E+26"
const [digit, decimal] = largeNumber.toLowerCase().split(".");
const [decimals, power] = decimal.split('e+');
const zerosToFill = power - decimals.length;
const zeros = Array(zerosToFill).fill(0);
const fullNumber = [digit, decimals, ...zeros].join('');
console.log(`${largeNumber} => ${fullNumber}`);
Use .toLocaleString
var a=7.125693126643573E26;
console.log(a.toLocaleString()); `//output -> 712,569,312,664,357,300,000,000,000`
console.log(a.toLocaleString('aa', { useGrouping: false })); `//output -> 712569312664357300000000000`
This will remove grouping also.
But it will make your number a string.
Use the built in function Number
let number=Number("7.125693126643573E26")
you can also convert it using Math
let number=("7.125693126643573e+26")
parts = String(number).toLowerCase().split('e'),
e = parts.pop(),
l = Math.abs(e),
sign = e/l,
coeff_array = parts[0].split('.');
var dec = coeff_array[1];
if(dec) l = l - dec.length;
num = coeff_array.join('') + new Array(l+1).join('0');
alert(num)
I have the following code that calculates and shows the sum of two values.
var oldprice_formated = parseFloat(oldprice).toFixed(2);
var extraPrice = parseFloat(3).toFixed(2);
if(initials != '') {
var new_price = oldprice_formated + extraPrice;
$('.product-detail .woocommerce-Price-amount.amount').html('<span>€</span>'+new_price);
} else {
$('.product-detail .woocommerce-Price amount.amount').html('<span>€</span>'+oldprice_formated);
}
For example:
oldprice_formated = parseFloat(49.99).toFixed(2);
extraPrice = parseFloat(3.00).toFixed(2)
The expected result: Sum is 52.99
Actual result: Sum is 49.003.00
What am I doing wrong? I assume it's with the number parsing, but not sure what I should change to make it work correctly. Thanks!
.toFixed() returns a string, not a number with only two decimal places.
oldprice_formated = parseFloat(49.99).toFixed(2); // "49.99"
extraPrice = parseFloat(3.00).toFixed(2); // "3.00"
When adding those two variables, instead of a number sum, you're concatenating two strings:
"49.99" + "3.00"; // "49.993.00"
I believe this is what you'll want to do:
var new_price = parseFloat(oldprice_formated) + parseFloat(extraPrice);
Or simply run .toFixed() after you sum those values which were already parsed to floats.
Because toFixed() returns a string, the + operator acts as a string concatenator. If you want it to operate as an addition operator, you must typecast your values as numbers:
let oldprice = 49.99;
let oldprice_formatted = parseFloat(oldprice).toFixed(2);
let extraPrice = parseFloat(3).toFixed(2);
console.log(`string concatenation: ${oldprice_formatted + extraPrice}`)
console.log(`type conversion: ${+oldprice_formatted + +extraPrice}`)
I have simple function that calculates number of decimals,
eg. _d(0.01) = 2, _d(0.001) = 3 and so on.
We added some new coins to our system that have 0.00000001 quantity and function broke.
Here is why:
0.00000001.toString() = 1e-8, so I cant split it it by '.' and calculate length of second part as I did before.
So the question is - how to get string '0.00000001' out of 0.00000001 number easiest way.
EDIT
I didnt mean exactly '0.00000001', I meant any micronumber to decimal without exp. Some function _d(x) that would work _d(0.000000000012) = '0.000000000012'and so on. What usually toString() does to large (but not too large) numbers.
Use toFixed() with a large number of digits, then count the number of zeroes after the decimal point.
function _d(num) {
var str = num.toFixed(100);
var fraction = str.split('.')[1];
var zeros = fraction.match(/^0*/)[0].length;
return zeros + 1;
}
console.log(_d(0.1));
console.log(_d(0.01));
console.log(_d(0.000000001));
Do you want some thing like this
function decimalPlaces(num) {
var match = (''+num).match(/(?:\.(\d+))?(?:[eE]([+-]?\d+))?$/);
if (!match) { return 0; }
return Math.max(
0,
// Number of digits right of decimal point.
(match[1] ? match[1].length : 0)
// Adjust for scientific notation.
- (match[2] ? +match[2] : 0));
}
console.log(decimalPlaces(0.000000001))
First off, I got some inspiration for this answer from here:
How to avoid scientific notation for large numbers in JavaScript?
You can convert the number to a strong and then check for str.indexOf("e"). If true, then just return the scientific notation part of the string. For example:
function _d() {
// your current function here
if (str.indexOf("e")) {
var something = str.split("-")[1];
return something;
}
}
EDIT: I was working on this before your last comment to me, so this returns a string of the number, which I thought was what you wanted.
Leaving aside the point about significant digits, which is meaningful and correct but does not solve your problem, try this. We take the number, convert to string, if that string is not scientific notation then the answer is trivial. If it is scientific notation, then split the string twice (once on "e-" and then split the zeroth array on "." Add str[1]-1 zeroes to the lead of the number and add the digits to the end.
function _d(arg) {
var str = arg.toString();
if (str.indexOf("e-")) {
var digits = str.split("e-")[0];
var zeroes = str.split("e-")[1];
var zero = Number(zeroes);
var each = digits.split(".");
var something = "0.";
for (var i = 0; i < zeroes-1; i++) {
something += "0";
}
for (var j = 0; j < each.length; j++) {
something = something + each[j];
}
return something;
}
}
This won't work with very large numbers or very small negative numbers. And its pretty convoluted.
The other way is to use .toString() and then look for .length-2(2 characters - '0.'. It should give you the number of zeros.
The advantage of this method is you don't need to know the number of maximum decimals in the number.
To keep it as the full decimal:
Number(0.000001)
// 0.000001
To show it as a string:
0.000001.toFixed(6)
// "0.000001"
What is the proper way to add the sum of multiple variables in Javascript?
This is what I'm trying to do. I've tried it with and without the quotes around my variables. I'm not getting a NaN or an Undefined or anything. No output whatsoever.
function setstat(){
document.getElementById('date').value = window.opener.document.getElementById('thisday').value;
document.getElementById('name').value = window.opener.document.getElementById('element_7').value;
document.getElementById('time').value = window.opener.document.getElementById('stwa').value;
inbcalls = window.opener.document.getElementById('element_6').value;
document.getElementById('totinb').value = inbcalls;
inbcallsp = parseInt("inbcalls",10);
asaptotal = window.opener.document.getElementById('asapcalls').value;
document.getElementById('asaptot').value = asaptotal;
asaptotalp = parseInt("asaptotal",10);
faxtotal = window.opener.document.getElementById('faxcalls').value;
document.getElementById('faxtot').value = faxtotal;
faxtotalp = parseInt("faxtotal",10);
obtotal = window.opener.document.getElementById('obcalls').value;
document.getElementById('obtot').value = obtotal;
totalcalls = inboundcallsp + asaptotalp + faxtotalp + obtotalp;
document.getElementById('totsum').value = totalcalls;
}
Why are you quoting the variable names?
inbcallsp = parseInt("inbcalls",10);
should be:
inbcallsp = parseInt(inbcalls, 10);
And the same for the rest of them. You want to parse the value of the variables, not the names of the variables; those will always result in NaN.
asaptotalp = parseInt("asaptotal",10);
"asaptotal" is recognize as the string not the variable
you should not quote it
When using parseInt always specify the radix as 10.
The function singnature: parseInt(string, radix)
The radix is optional but if ommited, JavaScript assumes the following:
If the string begins with "0x", the radix is 16 (hexadecimal)
If the string begins with "0", the radix is 8 (octal). This feature is deprecated
If the string begins with any other value, the radix is 10 (decimal)
Example:
parseIn("05") ==== 0 -> true
parseIn("05", 10) ==== 5 -> true
Don't use ParseInt, sometimes it will not return the proper value.
Better use Number, for example:
var i=Number(your value)