How do I convert an integer in JavaScript to a 32bits? [duplicate] - javascript

This question already has answers here:
How do you convert numbers between different bases in JavaScript?
(21 answers)
Closed 5 months ago.
I have some numbers (base 10) that I want to convert to a 32 bits(base 2), I have tried a lot of things, I found out the >>> operator, but apparently it only converts negative numbers to a base 10 the equivalent of the 32 bits, instead of base 2
const number = 3
const bitNumber = 1 >>> 0
console.log(bitNumber) /// 1

The numbers are always stored as bits internally. It’s console.log that converts them to a string, and the string conversion uses decimal by default.
You can pass a base to Number.prototype.toString:
console.log(bitNumber.toString(2));
and display as many bit positions as you want:
console.log(bitNumber.toString(2).padStart(32, '0'));

Related

convert string representation of float to number - keep decimals the same [duplicate]

This question already has an answer here:
Keep trailing or leading zeroes on number
(1 answer)
Closed 9 months ago.
I have some string values like "35.5" , "32.20" and I want them to be converted to numbers but keep the exact same decimals. When I use Number("32.0") for example I get 32 but I want 32.0. If I convert Number("35.5") I want 35.5 not 35.50, is there any way to do this easily?
if you want a fixed number of floating point you can use toFixed but be aware that returns a string
const strings = [ "35.5" , "32.20", "32.0"]
const result = strings.map(n => parseFloat(n).toFixed(1))
console.log(result)

Javascript: Subtracting a whole integer from a integer with a decimal alters the decimal value? [duplicate]

This question already has answers here:
Is floating point math broken?
(31 answers)
Get decimal portion of a number with JavaScript
(29 answers)
Closed 3 years ago.
The goal is to isolate the decimal value (with simply turning the integer into a string and splitting it).
To that affect I have:
var x = 1001.1;
var roundedDown = Math.floor(x); // Produces 1001
var decimal = x - roundedDown;
The expected value of decimal should be 0.1 (1001.1 - 1001). But instead I get 0.0999999 recurring.
I have tried with Math.trunc as well but get the same results.
Would anyone know why this is?

Why does a JavaScript function automatically convert a binary number when I pass it as an argument? [duplicate]

This question already has answers here:
Number with leading zero in JavaScript
(3 answers)
Closed 3 years ago.
I guess I can format it back. I'm just interested in why it's happening.
function test(d){
console.log(d) // 151028224
}
console.log(test(00001100101000))
By default, any number literally written with a zero at the beginning is considered as octal (base 8) number representation, and then, when you show back any number with console.log, it is written as its base 10 representation.
console.log(05)
console.log(06)
console.log(07)
console.log(010)
console.log(011)
It's recommended to avoid this in code, because it can lead to confusions :
if the number contains the digits 8 or 9, it cannot be a base-8 number, and thus treated as base 10 !
console.log(05)
console.log(06)
console.log(07)
console.log(08) // Yiiik !
console.log(09) // Yiiik !
console.log(010)
console.log(011)
The function has nothing to do with it.
The JavaScript compiler converts your number literal into a Number when it compiles the source code.
Since the number starts with a 0, it is treated as octal instead of decimal.

JS number function adds up zeros at the end [duplicate]

This question already has answers here:
JavaScript summing large integers
(10 answers)
Closed 5 years ago.
I am using the Number() JS function which is supposed to convert string value to numeric.
It's working fine for small numbers. For big ones - it is starting to substitude values with zeros as shown on the image:
Is there a work around for this problem?
In JS, the largest integral value is 9007199254740991 That is, all the positive and negative integers should not exceed the -9007199254740991 and 9007199254740991 respectively.
The same is defined as the 253-1.
console.log(Number.isSafeInteger(parseInt('1111111111')))
console.log(parseInt('1111111111'))
console.log(Number.isSafeInteger(parseInt('111111111111111111')))
console.log(parseInt('111111111111111111'))
//9007199254740991 - The largest JS Number
console.log(Number.isSafeInteger(parseInt('9007199254740991')))
This is because you're using numbers that are larger than Number.MAX_SAFE_INTEGER and Javascript does not guarantee to represent these numbers correctly
Use Number.isSafeInteger to check:
> Number.isSafeInteger(Number('111111111111111111'))
< false

Converting Decimal Number to Binary [duplicate]

This question already has answers here:
What is the JavaScript >>> operator and how do you use it?
(7 answers)
How do I convert an integer to binary in JavaScript?
(17 answers)
Closed 5 years ago.
I found this code on W3schools for converting decimal into binary.
function dec2bin(dec){
return (dec >>> 0).toString(2);
}
I don't understand what is the purpose for making zero fill right shift in this case? What is the use of setting the shift to 0 (i.e. dec >>> 0) since as I know it doesn't push any binary digit to the right at all?
I am a JS beginner. Thanks!

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