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.
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)
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:
Truncate number to two decimal places without rounding
(43 answers)
Closed 2 years ago.
is there a way to have 2 numbers after comma without rounding the value. I want the exact value. Math.round() and toFixed() give the value rounded.
You can do the workaround with help of Math.ceil() and Math.floor() functions.
Another way, is treat is as an string and use .slice()
i.e:
number = number.slice(0, number.indexOf(".")+3); //this should give you 2 decimals
Number(number); //Convert it to "Number" again, so you can operate with it
Solution without type conversions
While solving the issue, you should bear in mind that bouncing back and forth between data types may cost you some of app performance wasted
Instead, I'd suggest to modify input number directly:
shift the dot n positions to the right by multiplying your number by 10 in power of n (10**n)
cut off what's left after dot, using bitwise OR (|) that implicitly turns the float into integer
divide the result by 10 in power of n to shift the dot n positions back to the left
Following is a quick live-demo:
const num = 3.14159265,
precision = 4,
limitPrecision = (n,p) => (0|n*10**p)/10**p
console.log(limitPrecision(num, precision))
.as-console-wrapper{min-height:100%;}
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.
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 7 years ago.
I have data like this:
var currentValue="12345678901234561";
and I'm trying to parse it:
var number = parseInt(currentValue, 10) || 0;
and my result is:
number = 12345678901234560
now lets try:
currentValue="12345678901234567"
in this case parseInt(currentValue,10) will result in 12345678901234568
Can anyone explain me why parseInt is adding/substracting 1 from values provided by me?
Can anyone explain me why parseInt is adding/substracting 1 from values provided by me?
It's not, quite, but JavaScript numbers are IEEE-754 double-precision binary floating point (even when you're using parseInt), which have only about 15 digits of precision. Your number is 17 digits long, so precision suffers, and the lowest-order digits get spongy.
The maximum reliable integer value is 9,007,199,254,740,991, which is available from the property Number.MAX_SAFE_INTEGER on modern JavaScript engines. (Similarly, there's Number.MIN_SAFE_INTEGER, which is -9,007,199,254,740,991.)
Some integer-specific operations, like the bitwise operators ~, &, and |, convert their floating-point number operands to signed 32-bit integers, which gives us a much smaller range: -231 (-2,147,483,648) through 231-1 (2,147,483,647). Others, like <<, >>, and >>>, convert it to an unsigned 32-bit integer, giving us the range 0 through 4,294,967,295. Finally, just to round out our integer discussion, the length of an array is always a number within the unsigned 32-bit integer range.