var intvalue = Math.floor( floatvalue );
var intvalue = Math.ceil( floatvalue );
var intvalue = Math.round( floatvalue );
// `Math.trunc` was added in ECMAScript 6
var intvalue = Math.trunc( floatvalue );
Math object reference
Examples
Positive// value=x // x=5 5<x<5.5 5.5<=x<6
Math.floor(value) // 5 5 5
Math.ceil(value) // 5 6 6
Math.round(value) // 5 5 6
Math.trunc(value) // 5 5 5
parseInt(value) // 5 5 5
~~value // 5 5 5
value | 0 // 5 5 5
value >> 0 // 5 5 5
value >>> 0 // 5 5 5
value - value % 1 // 5 5 5
// value=x // x=-5 -5>x>=-5.5 -5.5>x>-6
Math.floor(value) // -5 -6 -6
Math.ceil(value) // -5 -5 -5
Math.round(value) // -5 -5 -6
Math.trunc(value) // -5 -5 -5
parseInt(value) // -5 -5 -5
value | 0 // -5 -5 -5
~~value // -5 -5 -5
value >> 0 // -5 -5 -5
value >>> 0 // 4294967291 4294967291 4294967291
value - value % 1 // -5 -5 -5
// x = Number.MAX_SAFE_INTEGER/10 // =900719925474099.1
// value=x x=900719925474099 x=900719925474099.4 x=900719925474099.5
Math.floor(value) // 900719925474099 900719925474099 900719925474099
Math.ceil(value) // 900719925474099 900719925474100 900719925474100
Math.round(value) // 900719925474099 900719925474099 900719925474100
Math.trunc(value) // 900719925474099 900719925474099 900719925474099
parseInt(value) // 900719925474099 900719925474099 900719925474099
value | 0 // 858993459 858993459 858993459
~~value // 858993459 858993459 858993459
value >> 0 // 858993459 858993459 858993459
value >>> 0 // 858993459 858993459 858993459
value - value % 1 // 900719925474099 900719925474099 900719925474099
// x = Number.MAX_SAFE_INTEGER/10 * -1 // -900719925474099.1
// value = x // x=-900719925474099 x=-900719925474099.5 x=-900719925474099.6
Math.floor(value) // -900719925474099 -900719925474100 -900719925474100
Math.ceil(value) // -900719925474099 -900719925474099 -900719925474099
Math.round(value) // -900719925474099 -900719925474099 -900719925474100
Math.trunc(value) // -900719925474099 -900719925474099 -900719925474099
parseInt(value) // -900719925474099 -900719925474099 -900719925474099
value | 0 // -858993459 -858993459 -858993459
~~value // -858993459 -858993459 -858993459
value >> 0 // -858993459 -858993459 -858993459
value >>> 0 // 3435973837 3435973837 3435973837
value - value % 1 // -900719925474099 -900719925474099 -900719925474099
Top answer 1 of 16
2261
var intvalue = Math.floor( floatvalue );
var intvalue = Math.ceil( floatvalue );
var intvalue = Math.round( floatvalue );
// `Math.trunc` was added in ECMAScript 6
var intvalue = Math.trunc( floatvalue );
Math object reference
Examples
Positive// value=x // x=5 5<x<5.5 5.5<=x<6
Math.floor(value) // 5 5 5
Math.ceil(value) // 5 6 6
Math.round(value) // 5 5 6
Math.trunc(value) // 5 5 5
parseInt(value) // 5 5 5
~~value // 5 5 5
value | 0 // 5 5 5
value >> 0 // 5 5 5
value >>> 0 // 5 5 5
value - value % 1 // 5 5 5
// value=x // x=-5 -5>x>=-5.5 -5.5>x>-6
Math.floor(value) // -5 -6 -6
Math.ceil(value) // -5 -5 -5
Math.round(value) // -5 -5 -6
Math.trunc(value) // -5 -5 -5
parseInt(value) // -5 -5 -5
value | 0 // -5 -5 -5
~~value // -5 -5 -5
value >> 0 // -5 -5 -5
value >>> 0 // 4294967291 4294967291 4294967291
value - value % 1 // -5 -5 -5
// x = Number.MAX_SAFE_INTEGER/10 // =900719925474099.1
// value=x x=900719925474099 x=900719925474099.4 x=900719925474099.5
Math.floor(value) // 900719925474099 900719925474099 900719925474099
Math.ceil(value) // 900719925474099 900719925474100 900719925474100
Math.round(value) // 900719925474099 900719925474099 900719925474100
Math.trunc(value) // 900719925474099 900719925474099 900719925474099
parseInt(value) // 900719925474099 900719925474099 900719925474099
value | 0 // 858993459 858993459 858993459
~~value // 858993459 858993459 858993459
value >> 0 // 858993459 858993459 858993459
value >>> 0 // 858993459 858993459 858993459
value - value % 1 // 900719925474099 900719925474099 900719925474099
// x = Number.MAX_SAFE_INTEGER/10 * -1 // -900719925474099.1
// value = x // x=-900719925474099 x=-900719925474099.5 x=-900719925474099.6
Math.floor(value) // -900719925474099 -900719925474100 -900719925474100
Math.ceil(value) // -900719925474099 -900719925474099 -900719925474099
Math.round(value) // -900719925474099 -900719925474099 -900719925474100
Math.trunc(value) // -900719925474099 -900719925474099 -900719925474099
parseInt(value) // -900719925474099 -900719925474099 -900719925474099
value | 0 // -858993459 -858993459 -858993459
~~value // -858993459 -858993459 -858993459
value >> 0 // -858993459 -858993459 -858993459
value >>> 0 // 3435973837 3435973837 3435973837
value - value % 1 // -900719925474099 -900719925474099 -900719925474099
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348
Bitwise OR operator
A bitwise or operator can be used to truncate floating point figures and it works for positives as well as negatives:
function float2int (value) {
return value | 0;
}
Results
float2int(3.1) == 3
float2int(-3.1) == -3
float2int(3.9) == 3
float2int(-3.9) == -3
Performance comparison?
I've created a JSPerf test that compares performance between:
Math.floor(val)val | 0bitwise OR~~valbitwise NOTparseInt(val)
that only works with positive numbers. In this case you're safe to use bitwise operations well as Math.floor function.
But if you need your code to work with positives as well as negatives, then a bitwise operation is the fastest (OR being the preferred one). This other JSPerf test compares the same where it's pretty obvious that because of the additional sign checking Math is now the slowest of the four.
Note
As stated in comments, BITWISE operators operate on signed 32bit integers, therefore large numbers will be converted, example:
1234567890 | 0 => 1234567890
12345678901 | 0 => -539222987
Reddit
reddit.com › r/typescript › trying to create a floating point type?
r/typescript on Reddit: Trying to create a floating point type?
November 13, 2023 -
Hey all, the work I'm currently doing involves me receiving all of my values from some machines as a long string, with all of our variables separated by commas. The problem is that a lot of these values have floating numbers that require a set amount of decimal accuracy, so I can have something like 10.0000 that I would like to maintain as a valid number. Is there any way I can create some sort of type that can maintain the floating zeroes as a value like a string, but be treated as a number? I'm just sick of typing all of our variables with names like somethingNumber: string, it's driving me bananas.
Top answer 1 of 7
14
You could represent 10.0000 as an object, such as {int: BigInt(10_0000), shift_10: 4}. This will let you store and report an arbitrary level of precision, though it will be more cumbersome to use than JS’s built-in floating-ish-point number type.
2 of 7
4
Terminology thing: (not trying to be a pedant so much as, like, if you know the terminology better you can google this better) The thing you're describing is not really floating point. I think some languages call this BigDecimal, probably you can google for JS/TS libraries that do this. (Even if you make your own implementation instead of using a library, which it seems you want, you might find it useful to peek at some prior art)
Code Highlights
code-hl.com › home › javascript › tutorials
5 Easy Ways to Convert JavaScript Float to Int | Code Highlights
June 4, 2024 - All these methods are compatible with major web browsers, including Chrome, Firefox, Safari, Edge, and Internet Explorer. This ensures that your code will run smoothly across different environments. In this tutorial, we explored five simple methods to convert a JavaScript float to an int:
Delft Stack
delftstack.com › home › howto › javascript › javascript float to int
How to Convert a Float Number to Int in JavaScript | Delft Stack
February 2, 2024 - We can apply the bitwise right shift operator (represented by >> characters). It will convert the float value to an integer. Underneath at the binary level, the bitwise right SHIFT operator shifts the binary bits of the operand to the right ...
Tutorial Teacher
tutorialsteacher.com › typescript › typescript-number
TypeScript number Data Type
In the above example, let first:number = 1; stores a positive integer as a number.let second: number = 0x37CF; stores a hexadecimal as a number which is equivalent to 14287. When you print this number on your browser's console, it prints the equivalent floating point of the hexadecimal number.let third:number=0377; stores an octal number equivalent to 255.
Internet Computer Developer Forum
forum.dfinity.org › developers
Convert a Float number to an Int type - Developers - Internet Computer Developer Forum
June 10, 2024 - I am trying to convert a float number to an integer. The reason is that I want the E8S equivalent of 1 ICP of a value, for example 1.15. This should be 115_000_000, but the function returns 114_000_000. Other values are calculated correctly, for example 1.25 = 125_000_000 or 0.9 = 90_000_000. public func convertFloatToNat(x: Float): async Int { let ONE_ICP_IN_E8S = 100_000_000; Debug.print("convertFloatToNat "#debug_show(x)); let a = x * 100; Debug.print("float x 100 = "#...
TutorialsPoint
tutorialspoint.com › how-do-i-convert-a-float-number-to-a-whole-number-in-javascript
How do I convert a float number to a whole number in JavaScript?
In the above output users can see that Math.trunc() method has removed the decimal part and Math.round() method has rounded the number to nearest integer. In this approach, we will use the parseInt() method. The parseInt() method extracts the whole number from the float number or string in ...
Byby
byby.dev › js-float-to-int
How to convert float to integer in JavaScript
You can use various methods that either round, truncate, or parse the float value. Depending on your specific use case, you can choose the most appropriate method: Using Math.trunc(). This method returns the integer part of a number by removing any fractional digits.
Top answer 1 of 7
48
Great Question! I actually had to deal with this the other day! It may seem like a goto to just write parseInt but wait! we can be fancier.
So we can use bit operators for quite a few things and this seems like a great situation! Let's say I have the number from your question, 12.345, I can use the bit operator '~' which inverts all the bits in your number and in the process converts the number to an int! Gotta love JS.
So now we have the inverted bit representation of our number then if we '~' it again we get ........drum roll......... our number without the decimals! Unfortunately, it doesn't do rounding.
var a = 12.345;
var b = ~~a; //boom!
We can use Math.round() for that. But there you go! You can try it on JSperf to see the slight speed up you get! Hope that helps!
2 of 7
14
this is a good example i think
var intvalue = Math.floor( floatvalue );
var intvalue = Math.ceil( floatvalue );
var intvalue = Math.round( floatvalue );
Webdevtutor
webdevtutor.net › blog › typescript-change-float-to-int
Converting Float to Int in TypeScript: A Comprehensive Guide
One of the simplest ways to convert a float to an integer in TypeScript is by using the Math.floor() method. This method rounds down a number to the nearest integer.
GitHub
github.com › Microsoft › TypeScript › issues › 21934
Understand 'int', 'integer', 'float', 'double', etc. as 'number' in JSDoc · Issue #21934 · microsoft/TypeScript
December 31, 2017 - All numeric-sounding names should probably resolve to number (maybe only if no other type is defined with such a given name). Ideas: [u]int[8|16|32|64] integer float double
Published Feb 14, 2018
GitBook
basarat.gitbook.io › typescript › recap › number
Number | TypeScript Deep Dive
console.log({max: Number.MAX_SAFE_INTEGER, min: Number.MIN_SAFE_INTEGER}); // {max: 9007199254740991, min: -9007199254740991} Safe in this context refers to the fact that the value cannot be the result of a rounding error.
TypeScript Tutorial
typescripttutorial.net › home › typescript tutorial › typescript number
TypeScript Number
October 18, 2024 - All numbers in TypeScript are either floating-point values or big integers. The floating-point numbers have the type number while the big integers get the type bigint. The following shows how to declare a variable that holds a floating-point value:
Rip Tutorial
riptutorial.com › float to integer
JavaScript Tutorial => Float to Integer
The floor function returns the first integer less than or equal to the float.
Webdevtutor
webdevtutor.net › blog › typescript-parse-float-to-int
How to Parse Float to Int in TypeScript
To convert a float value to an integer in TypeScript, you can use the parseInt() function. This function takes a string as its input and returns an integer after parsing the input.
Atomic Spin
spin.atomicobject.com › 2018 › 11 › 05 › using-an-int-type-in-typescript
Using an Int Type in TypeScript
November 5, 2018 - So even though I knew that the end result would always be a whole number, by forgetting about the inaccuracies of floating point numbers, I let a bug slip through. In order to ensure that the result is always an integer, as required by the PostgreSQL database, it needs to be rounded: ... Forgetting to round the result of a calculation, when you know full well the result should be a whole number, is very easy to do. A teammate suggested that we use TypeScript to force us to round the result by coming up with an Int type we could use whenever a value was going to be inserted into an integer column in the database.
Top answer 1 of 15
1
Copyfunction int(a) {
return a - a === 0 && a.toString(32).indexOf('.') === -1
}
function float(a) {
return a - a === 0 && a.toString(32).indexOf('.') !== -1
}
You can add typeof a === 'number' if you want to exclude strings.
2 of 15
1
YourJS provides the following two functions which work for all numbers including returning false for -Infinity and Infinity:
Copyfunction isFloat(x) {
return typeOf(x, 'Number') && !!(x % 1);
}
function isInt(x) {
return typeOf(x, 'Number') && x % 1 == 0;
}
Due to the fact that typeOf() is a YourJS internal function, if you wanted to use these definitions you can download the version for just these functions here: http://yourjs.com/snippets/build/34
Webdevtutor
webdevtutor.net › blog › typescript-cast-float-to-int
TypeScript: How to Cast Float to Int
Converting float numbers to integers in TypeScript is a common requirement in many applications. By using methods like Math.floor() and type assertions, you can easily cast float numbers to ints in TypeScript.
Luis Llamas
luisllamas.es › inicio › cursos › curso typescript
The Number Type in TypeScript
June 23, 2025 - TypeScript provides several ways to do this, including parseInt, parseFloat, and the unary + operator. let string: string = "42"; let integer: number = parseInt(string); // 42 let float: number = parseFloat("3.14"); // 3.14 let number: number ...
Medium
medium.com › interesting-coding › all-typescript-types-you-need-to-know-dd1423fd6687
All TypeScript Types You Need To Know | by Cihan | Interesting Coding | Medium
November 10, 2023 - In TypeScript, there are several built-in types that can be used to specify the type of a variable, function parameter, or function return value. These include: boolean: Represents a value that is either true or false. number: Represents a numeric value, either integer or floating-point.