Checking any equal values inside an array

[Eliaquim]

Hi people!

Well, after I see a lot of things on the internet, I can't figure that out.
I see some examples with .some() and with .every() but I can't manage to put it in my code and it works.

In the code below, the variables a,b,c will get a random value between 0 and 3.
So, if any of them are equal( a = b || a = c || b= c), then the code will make a random value again for each one of the variables. If not, the loop will break and the code will proceed.

my code:

var a, b, c, habitat;

function SetHabitat() {
a = Math.floor(Math.random()*4);
b = Math.floor(Math.random()*4);
c = Math.floor(Math.random()*4);
return;
};


for (var habitat = [a, b, c];; SetHabitat()) {
if((a !== b) && (a !== c) && (c !== b)) {
habitat = [a, b, c];
break;
}
};

console.log(habitat);

How can I check if are any equal values inside an array?

I manage to do that. But only when I specify the arrays.
But, in case that will be a lot of arrays. How can I make it simple? Like putting in the "if(any arrays are equal == false)" { then i execute my code}

Thanks!

 

[Jonforum]

    var habitat = [];
    while(habitat.length < 3){ // while will break when you will get 3 unique random data in array
        const r = ~~(Math.random()*4);
        (habitat.indexOf(r) === -1) && habitat .push(r); // if not unique, add value
    }

 

[Eliaquim]

    var habitat = [];
    while(habitat.length < 3){ // while will break when you will get 3 unique random data in array
        const r = ~~(Math.random()*4)
        (habitat.indexOf(r) === -1) && habitat .push(r); // if not unique, add value
    }

Thanks!
But I cannot seem to understand, I think.
With your code, I can substitute all of mine, right? Or I have to find out where I can put it?

If I change the number in here, "habitat.length < 3", to 6 for example, this will generate more length to the array, right?

Also, it gets "r is not defined"
I try to define it with var or const but didn't work.

Spoiler: image

what is the goal for "~~"?

 

[Poryg]

~~ is substitute od Math.floor.

As for the r, he forgot a semicolon at the end of the line. In some JS interpreters they are important.
Also, if const doesn't work, try var.
Either way it looks like it should work.

 

[Jonforum]

With your code, I can substitute all of mine, right? Or I have to find out where I can put it?

yes the code will add 3 random unique numbers inside the variable habitat . (never same)

Also, it gets "r is not defined"

Is you not use es6 change `const` by `var` sorry for this!

what is the goal for "~~"?

It a short ways to do `Math.floor`

 

[Jonforum]

i also recommend you create a function or method

    /** Generate n random unic habitat */
    generateHabitat = function(max,range) {
        var buffer = [];
        while(buffer.length < max){ // while will break when you will get max unique random data in array
            var r = ~~(Math.random()*range); // range between 0=>range
            (buffer.indexOf(r) === -1) && buffer .push(r); 
        }
        return buffer;
    }



    var habitat = generateHabitat(6,30);
    console.log('habitat: ', habitat); // return a arrays with 6 random unic number range between 0=>30

 

[Eliaquim]

i also recommend you create a function or method

    /** Generate n random unic habitat */
    generateHabitat = function(max,range) {
        var buffer = [];
        while(buffer.length < max){ // while will break when you will get max unique random data in array
            var r = ~~(Math.random()*range); // range between 0=>range
            (buffer.indexOf(r) === -1) && buffer .push(r);
        }
        return buffer;
    }



    var habitat = generateHabitat(6,30);
    console.log('habitat: ', habitat); // return a arrays with 6 random unic number range between 0=>30

Hi!!
I tested and it works!
But took me a while to understand it ^^''
The only things that I have doubt are this line:
"(buffer.indexOf(r) === -1) && buffer .push(r);"

why, indexOf(r) is equal to -1? What does that mean?
buffer .push(r); > This is for add another object inside the array, right?

 

[Jonforum]

yes , don't worry this forum it for learn.
indexOf return a index of the element founds in a arrays , but if found nothing, it return -1;
you could also write `buffer.indexOf(r) < 0` it will work.
so to translate this code line `(buffer.indexOf(r) === -1) && buffer .push(r);`
it like `check if r existe in buffer, if not? (index-1)...continue loop ,
if yes (index>-1) , add inside bufferArray r and continue loop`
more info here
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/indexOf

 

[Eliaquim]

yes , don't worry this forum it for learn.
indexOf return a index of the element founds in a arrays , but if found nothing, it return -1;
you could also write `buffer.indexOf(r) < 0` it will work.
so to translate this code line `(buffer.indexOf(r) === -1) && buffer .push(r);`
it like `check if r existe in buffer, if not? (index-1)...continue loop ,
if yes (index>-1) , add inside bufferArray r and continue loop`
more info here
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/indexOf

OHHHH!!
I get it now "indexOf return a index of the element founds in a arrays , but if found nothing, it return -1;"
Thanks! I learn a lot from all this! ^^

 

[mlogan]

This thread is being closed, due to being solved. If for some reason you would like this thread re-opened, please report this post and leave a message why. Thank you.