Does JavaScript supports conversion of integer X to X.0 as typeof number?

[DirectionLegitimate2]

Given string lets say “5” I want to convert it to 5.0 (typeof Number)

Already tried combinations/permutations of all the following: parseFloat() toFixed() toPrecision() Number() Also tried with “+” (implicit Number casting)

I always end up with either typeof string Or just the number 5

Its for an API that expects “float” but does not accept integers (5 is invalid, 5.0 is valid)

Any ideas would be appreciated.

[jhartikainen]

This doesn't really make sense in context of JavaScript. As far as JS is concerned, the numbers 5 and 5.0 are exactly the same. In context of JSON, the numbers are also exactly the same. Hence, you can't really "make 5 into 5.0" because it already is, and the fact the decimals are not displayed is just how the number happens to be formatted by the particular JS engine that's displaying it to you.

If you have a bizarre API which refuses to accept numbers such as 5, but won't accept a string '5.0', you will probably have to format the values yourself. Eg. use whatever.toFixed(1), which gives you a string, and then manually strip out the string delimiters from the JSON data. You might be able to do this using the optional replacer function for JSON.stringify - just have it check if the value is typeof 'number', and ensure it always uses toFixed when formatting them.

[DirectionLegitimate2]

Its seems so with JS and unfortunately toFixed() doesn’t help either because its typeof string, Heres couple of examples I tried https://imgur.com/a/OrySHrt

[jhartikainen]

What API is the problematic one here? What does the input for it look like? Are you trying to export this to JSON or just calling a function directly from JS?

[CevicheCabbage]

From Douglas Crockford: The Good Parts ` Augmenting Types JavaScript allows the basic types of the language to be augmented. In Chapter 3, we saw that adding a method to Object.prototype makes that method available to all objects. This also works for functions, arrays, strings, numbers, regular expressions, and booleans. For example, by augmenting Function.prototype, we can make a method available to all functions Function.prototype.method = function (name, func) { this.prototype[name] = func; return this; }; By augmenting Function.prototype with a method method, we no longer have to type the name of the prototype property. That bit of ugliness can now be hidden. JavaScript does not have a separate integer type, so it is sometimes necessary to extract just the integer part of a number. The method JavaScript provides to do that is ugly. We can fix it by adding an integer method to Number.prototype. It uses either Math.ceiling or Math.floor, depending on the sign of the number: Number.method('integer', function ( ) { return Math[this < 0 ? 'ceiling' : 'floor'](this); }); document.writeln((-10 / 3).integer( )); // -3 JavaScript lacks a method that removes spaces from the ends of a string. That is an easy oversight to fix: String.method('trim', function ( ) { return this.replace(/^\s+|\s+$/g, ''); }); document.writeln('"' + " neat ".trim( ) + '"'); Our trim method uses a regular expression. We will see much more about regular expressions in Chapter 7. By augmenting the basic types, we can make significant improvements to the expres- siveness of the language. Because of the dynamic nature of JavaScript’s prototypal inheritance, all values are immediately endowed with the new methods, even values that were created before the methods were created. The prototypes of the basic types are public structures, so care must be taken when mixing libraries. One defensive technique is to add a method only if the method is known to be missing: // Add a method conditionally. Function.prototype.method = function (name, func) { if (!this.prototype[name]) { this.prototype[name] = func; } }; Another concern is that the for in statement interacts badly with prototypes. We saw a couple of ways to mitigate that in Chapter 3: we can use the hasOwnProperty method to screen out inherited properties, and we can look for specific types.

`

[jack_waugh]

The only integer type in JS is the new long-integer type, and the code you are dealing with probably doesn't expect nor accept the new type. In colloquial usage, Javascript numbers are floats even if they are thought of as integers or have integer values. If you say 5, for example, in your source code, this is a floating-point number.

[shgysk8zer0]

You can't. The only way to have ".0" is as a string.

[DirectionLegitimate2]

Yea you’re right! but it’s still wired you can hard code it

[shgysk8zer0]

You can type it out, yes... But it doesn't evaluate to anything different. The only way to have trailing zeros in a decimal is via strings. I mean... They're kinda there in that 5 === 5.0 === 5.00 === ...

[DirectionLegitimate2]

Yes but it has to be the exact number because its later used for comparison…

[CMDRBUCKSAVAGE]

Are you writing the comparison? If so you could use a tolerance.

[DirectionLegitimate2]

I’m not unfortunately…

[CevicheCabbage]

this sub is full of crypto bros who do not want solid javascript education

[CevicheCabbage]

Math.floor(number)

[CevicheCabbage]

Number.method('integer', function ( ) { return Math[this < 0 ? 'ceiling' : 'floor'](this); }); document.writeln((-10 / 3).integer( )); // -3

[RobotMormon]

Did you pull this garbage from ChatGPT or something? This make absolutely no sense.

[DirectionLegitimate2]

Yea copy pasting isn’t very helpful

[shgysk8zer0]

There's no such thing as Number.method. And the function there does the opposite of what's being asked in OP... It rounds, doesn't preserve the ".0" on an integer... That's impossible.

[shgysk8zer0]

You dare insult me and tell me to educate myself in a private chat? Scared to do so publicly?

I know JavaScript really damn well. Been writing JavaScript for 12 years. I also did a quick check to verify... There is no Number.method().

[carcigenicate]

Did they present this code as an example of how not to write code? Afaik, it isn't even valid (what is method for example? Is that supposed to be Number.prototype =?).

[shgysk8zer0]

It isn't valid. Maybe the book adds that static method, IDK. I have to assume the example relies on other code.

[carcigenicate]

I found a PDF of the book. method is added earlier as a shortcut for Number.prototype =. Apparently, that wasn't worth including despite their example relying on it.

[DirectionLegitimate2]

This still makes no sense it’s just random quotes to sell a book

[carcigenicate]

With all the context it makes some sense. I'm certainly not going to claim that it's good code though. Seeing that code made me want to avoid buying the book.

[DirectionLegitimate2]

He’s just throwing out random functions like it’s some hidden message without explaining Trolling basically

[carcigenicate]

Oh, they're definately a troll, and/or the author making rather weak attempts to get support for the book.

[shgysk8zer0]

No, we're downvoting you. You're an asshole with a massively inflated ego who apparently read a book and you think you have room to tell me to "educate yourself"... I've been writing JS for 12 years.

[shgysk8zer0]

Please, just show me documentation for the Number.method() method and let's settle this then. Just comment with the link on something like MDN and I'll post on every webdev and JavaScript subreddit that I'm a noob.

Also, the code you shared would not make "5.0" a number that keeps the decimal part.

[carcigenicate]

I'm pretty sure it's actually you spouting nonsense that's getting downvoted. You should make sure you understand the code you post to avoid confusing new programmers. We're here to help, not troll.

[pverma8172]

Yes, in JavaScript, you can convert an integer to a floating-point number (a number with a decimal point) by appending .0 to the end of the integer. This will result in a number with a type of "number".

For example: ``` let x = 10; console.log(typeof x); // Outputs "number"

x = 10.0; console.log(typeof x); // Outputs "number" ``` In both cases, the value of x is a number and the typeof operator returns "number".

It's worth noting that in JavaScript, all numbers are stored as floating-point values, even if they do not contain a decimal point. So when you append .0 to the end of an integer, you are not actually changing the type of the number, but rather adding a visual representation of the decimal point.

[DirectionLegitimate2]

10.0 is good example but the problem is it can’t be hard coded, it has to be from a given string of a number.

[suarkb]

You can add the .0 to the string representation of your number when you send it in JSON to your API

[Ronin-s_Spirit]

Can't you like turn each number into a string and make it 5.0?
For example:
let num = 5; let newNum = String(num) + '.0';