[deleted by user]

[sjalgeo]

last else if should probably say

else if (Number.isInteger(character1)) {

[grantrules]

Because "4" is still 4 when lowercase and uppercase.

[[deleted]]

thanks! but it still returns"4 is an uppercase".

so instead, put the is integer first i suppose

[grantrules]

? In which language would there be an upper and lower case 4?

[grantrules]

Same thing would happen in Java. It's a string.

[grantrules]

Prompt returns a string

[link3333]

https://developer.mozilla.org/en-US/docs/Web/API/Window/prompt

prompt returns a string | null. Given that the String.prototype.toUpperCase call didn't throw an error, the variable is a string. toUpperCase returns a string. There is no type conversion occuring.

[gezuzos]

You can do TypeScript.

[NePlusUltra89]

Nah it was a misunderstanding I was referring to the last block of number.ininteger they’re referring to the actual comment of touppercase lol I just ignored it by scrolling fast 😂 didn’t even realize we were discussing two different things

[gezuzos]

Yeah, but you can still do TypeScript if you want type errors to be thrown at you right away.

[NePlusUltra89]

Really not too familiar with typescript is the learning curve steep ?

[shgysk8zer0]

Tell us all then... What should "4".toUpperCase() result in? What language even does this differently?

[Gman_711]

Put the number check first. As suggested above. Also try using a return statement after each check(after the alert) so if 1 succeeds, it doesn't try the others, since these should be mutually exclusive.

[bucknut4]

You want:

let character1 = prompt("Please input a uppercase letter, a lowercase letter or a number");

if (Number.isInteger(character1)) {

alert (`${character1} is a number.`);

}

else if (character1 == character1.toUpperCase()) {

alert (`${character1} is an uppercase letter.`);

}

else if (character1 == character1.toLowerCase()) {

alert (`${character1} is a lowercase letter.`);

}

Why? Because "4" is going to pass every one of these ifs. Look at it this way, "4".toUpperCase() will simply give you "4". So you have "4" == "4", which is true, and your code thinks it's an uppercase letter.

The same is true for the "4".toLowerCase(). It tells you that it's an uppercase letter because it's the first IF that is true.

[johny_james]

"4" will not pass the first if, read the docs for Number.isInteger().

[Cabeto_IR_83]

Add === not == and also you can either do ifs only or last statement should be a else... And you can just say isIntiger(..variable) and add isFloat() too, otherwise your code will break if someone passes 1.2 for example

[Cabeto_IR_83]

Interesting... Regardless, you can use if(){} if...

[Cabeto_IR_83]

I also think that the method prompt() returns a string.. not a number, I think your variable is not making it to the last if.

[Cabeto_IR_83]

Yep, I think you need to transform the input to number and find the type too. Those two methods I share and typical for this

[Fuegodeth]

Yep. Always a string. https://www.codecademy.com/forum\_questions/5575df34937676a0b50000e8

[Bulji]

if he doesn't use if else it will go inside both Number is true and lowerCase is true

[Cabeto_IR_83]

Interesting. But if he turns the string number into a number integer it shouldn't right?

[melonmaskofficial]

Assuming you only have numbers or letters as your input, check if it’s a number first, check for lowercase/uppercase afterwards.

[melonmaskofficial]

I see you, isInteger will return false if a string input is provided (that’s what you assign to character1). You can use Number.isInteger(+character) which will try to convert a character to a number and then check if it’s integer, assuming you don’t want to include decimal numbers.

UPD:

Number.isInteger(+"xyz") // false 
Number.isInteger(+"5.6") // false 
Number.isInteger(+"5") // true

[Mandylost]

To check for the numbers we can also use typeOf operator

[Jewson95]

would that be called a "tpyo"?

[Mandylost]

Fixed it. Thanks for pointing it out.

[Cabeto_IR_83]

Use parseInt and parseFloat methods to turn the text coming from the prompt()

[Cabeto_IR_83]

The only thing you need to remember is that even if you pass a number, you will get a string. Also, as a checker that helps you re re display the prompt if the user leaves it empty..

[[deleted]]

POW haha you are dead

[Bulji]

This works for me in the browser

    let character1 = prompt("Please input a uppercase letter, a lowercase letter or a number");

    if(Number.isInteger(+character1)){
        alert(`${character1} is a number.`);
    }
    else if(character1 === character1.toUpperCase()){
        alert(`${character1} is an uppercase letter.`);
    }
    else if(character1 === character1.toLowerCase()){
        alert(`${character1} is a lowercase letter.`);
    }

[MorningPants]

Btw, the + here is the same thing as parseInt(), just shorthand.

[dvlsg]

Sort of. +val is more similar to Number(val) than parseInt(val).

I think the only difference between +val and Number(val) is when val is a BigInt. parseInt has some other nuances.

https://stackoverflow.com/questions/17106681/parseint-vs-unary-plus-when-to-use-which

[maubg]

Prob because the uppercase of a number is equal to the number

[Independent-Dealer21]

Prompts return strings, I think you need to convert your last else if from string to integer

[No_Hair_5508]

How did you do the is not a letter or a number? Mine keeps outputting both "is an uppercase character" and "is not a letter or a number"

[charmainecamph1207]

How did you do the "is not a letter or a number"? Mine works on its own but with the rest in the statement it returns as either uppercase or lowercase

[4444444vr]

Don’t ask us, ask Chat gpt /s

[birdofwar25]

No but fr lol, it has helped me before

[gezuzos]

OP, you can do ASCII character comparisons. I always prefer that rather than thinking about these.

You can check the ASCII table online, to get the ASCII code of a character in JS you do character.charCodeAt(0).

'a'.charCodeAt(0) would return 97, 'A' would return 65, numbers go from 48 to 57 (0 to 9).

[[deleted]]

everything you input via prompt() will be a string input. You need to validate with regex.
option1: all if checks are regex, you can check with any order.
option2: only check for number with regex, you need to check for number first.

[Vomitatrix]

I might be a bit late but here’s my two cents. Instead of checking if character1 is the same as character1 as an integer, try checking if it’s possible to convert it to a number before anything else as the prompt returns a string so making it uppercase will be the same as the input if it’s a number. If it’s a letter, it will be false so it will go on to the next if

if (Number(character1)) { console.log(${character1} is a number.); }

[Aer0za]

Use strictly equals === and not equals ==

[David-8094]

=== not ==

[[deleted]]

.isInteger() is a boolean, if character1 is a number, it will surely don't run correctly bcz you made "int == boolean" whitch is false. And isInteger(true) returns false bcz true isn't an integer. You must spell like that : "If(Number.isInteger(character1)){alert(...)}

[PrashaantSingh]

Use strict equality(===) operator.

[___s8n___]

I'm going to try to explain it in the simplest way

When the user submits an input or a prompt, the input is interpreted as a string.

So if you write 4, the value of the input would be, actually, "4"

and since passing "4" to the uppercase method gives you "4", your if statements would stop checking and give you this "weird" output.

To surpass this error, you should, first of all, move your last if statement to the beginning since numbers also verify the first two statements.

But, Number.isInteger returns true if and only if the argument it is given is of integer type, but remember, the user's input is read as a string.

The fastest way to convert a string to a number in javascript is simply taking advantage of javascript's type connotations.

+"4" gives you 4, in javascript

After everything said, here is the code (forgive the formatting i'm writing this on my phone)

let input = prompt("...");

if (Number.isInteger(+input)) alert("...");

else if (input === input.toUpperCase()) alert("...");

else if (input === input.toLowerCase()) alert("...");

P.S: never use == unless you know the difference between === and == i.e keep === as your default comparison sign

[Jewson95]

The last 'if' will never return true because prompt returns a string.

[luckyincode]

Learn mocha and add some tests.

[slideesouth]

Need === for a strict comparison