CODEWITHSUNDEEP
javascriptecmascript-6map-functionnested-map
Cho Lin Tsai
Cho Lin Tsai

Reputation: 87

JS How to use nested map?

Here is the code, below the console.log part is my issue.

It logs out all 3 classes of offset in a tag like this :

<tag id="id1" class="$offset1, $offset2, $offset3">

But I just need 1 class of offset in a tag like this:

<tag id="id1" class="$offset1">

How do I fix this issue?

Explanation:

add new classes to html element

function $addClsls(element, ...newClass) {
    return element.classList.add(...newClass);
}

remove classes from html element

function $rmClsls(element, ...rmClass) {
    return element.classList.remove(...rmClass);
}

select an element id or class

function $select(element) {
    return document.querySelector(element);
}

a function to add or remove class from a selected element

function $switch(selectEle, eleClass, indexNum) {
    switch (indexNum) {
        case 0:
            $addClsls(selectEle, eleClass);
            break;
        case 1:
            $rmClsls(selectEle, eleClass);
            break;
        default:
    }
}

get 3 element ids into array

let groupElements = [$select('#id-1'), $select('#id-2'), $select('#id-
3')];

get 3 element classes into array(no need to put . )

let groupOffsets = ['offset1', 'offset2', 'offset3'];

set init time value

let addTime = 0;

check if true to map through groupElements and groupOffsets and set delay time

if (true) {
    groupElements.map( i => {
      setTimeout( () => {
        $switch(i, groupOffsets.map( x => x ), 0)
        console.log(i) // <= logs out results
      }, 0 + addTime );
      addTime += 1000;
    });
}

the GOAL is to log out like this : 

<tag id="id-1" class="offset1"> </tag>
<tag id="id-2" class="offset2"> </tag>
<tag id="id-3" class="offset3"> </tag>

but the issue is like this :

<tag id="id-1" class="offset1,offset2,offset3"></tag>
<tag id="id-2" class="offset1,offset2,offset3"></tag>
<tag id="id-3" class="offset1,offset2,offset3"></tag>

Upvotes: 0

Views: 1185

Answers (1)

Cho Lin Tsai
Cho Lin Tsai

Reputation: 87

Well, I got it fixed. So I'm gonna answer my own question. ;)

I tried another way to do map function, I used a 2-dimensional array instead of 2 separated arrays

let groupItems = [ 
    [$select('#id-1'), 'offset1'],
    [$select('#id-2'), 'offset2'],
    [$select('#id-3'), 'offset3']
]
groupitems.map( items => {
            setTimeout( () => {
                // destruct first dimensional
                let [ x ] = [items];
                // destruct second dimensional
                let [ i, j ] = x;
                // first round i = $select('#id-1'); j = 'offset2';
                // second and third round so forth
                sectionSwitch( i, j, 1);
            }, 0 + addTime);
            addTime += 1000;
        })

Upvotes: 1

Related Questions