This question already has answers here:
javascript large integer round because precision? (why?)
(2 answers)
What is JavaScript's highest integer value that a number can go to without losing precision?
(21 answers)
Closed 7 years ago.
number 10205558742352809 gets reduced to 10205558742352808.
What?
TL;DR: Floating-point numbers can be screwy.
Long Answer
Javascript uses 64-bit floating point numbers (IEEE-754). The binary that makes up a floating point number is composed of 3 parts: sign bit (1 bit), exponent field (11 bits), and the significand field (52 bits). There are plenty of sources online that go into further detail about how this works.
If we convert 10205558742352809 to it's binary format then interpret that as hexadecimal for readability we get:
434220F367C941D4
Which is the same thing you'd get for 102...09. Compare that with 102...10:
434220F367C941D5
So 102...09 is not directly representable in IEEE-754 and in fact lies on the border between 102...08 and 102...10.
Related
This question already has answers here:
What is JavaScript's highest integer value that a number can go to without losing precision?
(21 answers)
Closed 4 days ago.
I was expecting 6145390195186705543 but gave me 6145390195186705000.
This is my code:
var str = '6145390195186705543';
var num = parseInt(str);
console.log(num)
JavaScript uses 64-bit floating point numbers, which can represent numbers in the range -(2^53 - 1) to (2^53 - 1). In this case, the number 6145390195186705543 is out of this range and cannot be accurately represented in JavaScript. When trying to convert the string "6145390195186705543" to a number using the parseInt() function, JavaScript cannot represent the number exactly and rounds it to the nearest floating point number, resulting in 6145390195186705000.
To work with such large numbers, you can use special libraries for working with large arithmetic, such as BigInt or BigNumber.
This question already has answers here:
What is JavaScript's highest integer value that a number can go to without losing precision?
(21 answers)
How to convert a String to long in javascript?
(2 answers)
Closed 10 months ago.
A quick maybe simple question :
We are trying to parse a string into number , the sample number is "1928433000460244141" so when we try to parse it to integer we get 1928433000460244200
const no1 = "1928433000460244141" ;
console.log(parseInt(no1)); // returns 1928433000460244200
what can cause this problem and what is the solution ?
BigInt can be used to store the data , but the problem is we want to send the string converted to number to a service we are using right now , we do not have any access hence it is a 3rd party service so we should handle it from our side.
The MAX_SAFE_INTEGER constant has a value of 9007199254740991 (9,007,199,254,740,991 or ~9 quadrillion). The reasoning behind that number is that JavaScript uses double-precision floating-point format numbers as specified in IEEE 754 and can only safely represent integers between -(2^53 - 1) and 2^53 - 1.
Source
Because your number is larger than the safe integer limit, you're likely experiencing some floating-point precision issues that are rounding the value off.
This question already has answers here:
Node.js Maximum Safe Floating-point Number
(4 answers)
What is JavaScript's highest integer value that a number can go to without losing precision?
(21 answers)
Is floating point math broken?
(31 answers)
Closed 2 years ago.
I am developing a react app and i need to format some numbers using toLocaleString function and i realize that the decimal part of the number changes to zero when the number is very
(10000.25).toLocaleString('en',{maximumFractionDigits: 2, minimumFractionDigits: 2});
//Output: 10,000.25
(10000000000000000000.25).toLocaleString('en',{maximumFractionDigits: 2, minimumFractionDigits: 2});
//Output: 10,000,000,000,000,000,000.00
why is this so? is it a bug or am I missing something?
Javascript compiler cannot handle very large numbers. Use Number.MAX_SAFE_INTEGER to check the last number it can handle. Try to consider using string type from the beginning if these numbers are not calculated (Maybe if you get it from an API kind of), or try using BigInt type.
For floating point, the maximum number it can handle to a precision of 1 decimal digit is 562949953421311 and it differs for other digits. This has been referred here. Try using the BigNumber class in your case.
This question already has answers here:
Why are two different numbers equal in JavaScript?
(4 answers)
How to deal with floating point number precision in JavaScript?
(47 answers)
Is floating point math broken?
(31 answers)
Closed 3 years ago.
Why 888888888888888888888 equals 888888888888888900000 in JavaScript
console.log(888888888888888888888 === 888888888888888900000)
in chrome console
That is because integers can only be precisely represented in JavaScript up to 2^53 - 1
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/MAX_SAFE_INTEGER
The problem is that, after 2^53 - 1, there is not enough bits to represent the number. So, when you set a higher number, you lose information and what you are actually storing in memory is not reliable. In your case, these 2 numbers, after converting to binary, are the same. That is why they are equal
This question already has answers here:
Large numbers erroneously rounded in JavaScript
(6 answers)
Javascript parseInt() with leading zeros
(7 answers)
Closed 7 years ago.
I'm trying to convert a string to number in Javascript, but here is my problem :
var string = "068999999501111443";
parseInt(string); // 68999999501111440
Number(string); // 68999999501111440
Why does this happen and how to fix it ?
Thanks
This is because the number is too large to be stored accurately. It is being stored as a floating point number, which can only store a certain amount of precision. Beyond it's maximum precision, you'll get what look like weird rounding errors.
You'll get similar effects for decimals with a large number of decimal places. This is more well known, as it tends to occur more often, but it's exactly the same effect that is happening here.