Run results for: ClassList v5

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_6) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/13.1.2 Safari/605.1.15

Browser: Safari 13

Operating system: Mac OS X 10.15.6

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
forEach	2038.1 Ops/sec
Recursive outer	1353.2 Ops/sec
Recursive flatten	1549.7 Ops/sec

Script Preparation code:

var obj = {};

for (i = 1000; i > 0; i--) {
  if (i%2 == 0) {
  	obj[i] = 'String';
  } else {
    obj[i] = [ 'Array of String', 'Array of String' ];
  }
}

​x
 
var obj = {};​for (i = 1000; i > 0; i--) {  if (i%2 == 0) {    obj[i] = 'String';  } else {    obj[i] = [ 'Array of String', 'Array of String' ];  }}​

Tests:

forEach

function ClassList(collection={}) {
    const classNames = {};
    const keys = Object.keys(collection);

    keys.forEach((key) => {
        const innerCollection = collection[key];
        const collectionCheck = Object.prototype.toString.call(innerCollection);

        switch (collectionCheck) {
        case '[object Object]': {
            const innerKeys = Object.keys(innerCollection);

            if (innerKeys.length === 0) {
                classNames[key] = '';
                break;
            }

            let classList = [];
            innerKeys.forEach((innerKey) => {
                if (!innerCollection[innerKey] || !innerCollection[innerKey].length) {
                    return;
                }

                const innerCollectionCheck = Object.prototype.toString.call(innerCollection[innerKey]);
                switch (innerCollectionCheck) {
                case '[object Array]':
                    classList.push(...innerCollection[innerKey]);
                    break;

                case '[object String]':
                    classList.push(innerCollection[innerKey]);
                    break;
                }
            });

            classNames[key] = classList.reduce((acc, cl) => (acc += cl + ' '), '');
            break;
        }

        case '[object Array]':
            classNames[key] = innerCollection.reduce((acc, cl) => (acc += cl + ' '), '');
            break;

        case '[object String]':
            classNames[key] = innerCollection;
            break;
        }
    });

    return classNames;
}

ClassList( obj );

 
function ClassList(collection={}) {    const classNames = {};    const keys = Object.keys(collection);​    keys.forEach((key) => {        const innerCollection = collection[key];        const collectionCheck = Object.prototype.toString.call(innerCollection);​        switch (collectionCheck) {        case '[object Object]': {            const innerKeys = Object.keys(innerCollection);​            if (innerKeys.length === 0) {                classNames[key] = '';                break;            }​            let classList = [];            innerKeys.forEach((innerKey) => {                if (!innerCollection[innerKey] || !innerCollection[innerKey].length) {                    return;                }​                const innerCollectionCheck = Object.prototype.toString.call(innerCollection[innerKey]);                switch (innerCollectionCheck) {                case '[object Array]':                    classList.push(...innerCollection[innerKey]);                    break;​                case '[object String]':                    classList.push(innerCollection[innerKey]);                    break;                }            });​            classNames[key] = classList.reduce((acc, cl) => (acc += cl + ' '), '');            break;        }​        case '[object Array]':            classNames[key] = innerCollection.reduce((acc, cl) => (acc += cl + ' '), '');            break;​        case '[object String]':            classNames[key] = innerCollection;            break;        }    });​    return classNames;}​ClassList( obj );

Recursive outer

function rec(classList, key, collection = {} ) {

    return Object.values( collection ).reduce( (acc, col) => {        
        const colCheck = Object.prototype.toString.call(col);

        switch (colCheck) {
        case '[object Object]': {
            if ( Object.keys(col).length === 0 ) {
                acc[key] = '';
                break;
            }
            rec(classList, key, col );
            break;
        }
    
        case '[object Array]':
            acc[key] += col.join(' ') + ' ';
            break;
    
        case '[object String]':
            acc[key] += col + ' ';
            break;

        }

        return acc;

    }, classList );
}

function ClassList(collection = {}) {
    const keys = Object.keys(collection);
    
    return keys.reduce( (classList, key) => {
        switch (Object.prototype.toString.call(collection[key]) ) {
        case '[object Object]': {
            classList[key] = '';
            if ( Object.keys(collection[key]).length === 0 ) {
                break;
            }
            rec(classList, key, collection[key] );
            break;
        }
    
        case '[object Array]':
            classList[key] = collection[key].join(' ') + ' ';
            break;
    
        case '[object String]':
            classList[key] = collection[key] + ' ';
            break;

        }

        return classList;

    }, {} );
}

ClassList( obj );

 
function rec(classList, key, collection = {} ) {​    return Object.values( collection ).reduce( (acc, col) => {                const colCheck = Object.prototype.toString.call(col);​        switch (colCheck) {        case '[object Object]': {            if ( Object.keys(col).length === 0 ) {                acc[key] = '';                break;            }            rec(classList, key, col );            break;        }            case '[object Array]':            acc[key] += col.join(' ') + ' ';            break;            case '[object String]':            acc[key] += col + ' ';            break;​        }​        return acc;​    }, classList );}​function ClassList(collection = {}) {    const keys = Object.keys(collection);        return keys.reduce( (classList, key) => {        switch (Object.prototype.toString.call(collection[key]) ) {        case '[object Object]': {            classList[key] = '';            if ( Object.keys(collection[key]).length === 0 ) {                break;            }            rec(classList, key, collection[key] );            break;        }            case '[object Array]':            classList[key] = collection[key].join(' ') + ' ';            break;            case '[object String]':            classList[key] = collection[key] + ' ';            break;​        }​        return classList;​    }, {} );}​ClassList( obj );

Recursive flatten

function ClassList(collection = {}) {
    const result = {};

    function flatten(node, str) {
        const nodeType = Object.prototype.toString.call(node);
        
        switch (nodeType) {
            case '[object String]': {
                str += node + ' ';
                break;
            }
            case '[object Array]': {
                str += node.join(' ') + ' ';
                break;
            }
            case '[object Object]': {
                for (const key in node) {
                    str += flatten(node[key], '');
                }
                break;
            }
        }
        
        return str;
    }

    for (const key in collection) {
        result[key] = flatten(collection[key], '').trimEnd();
    }

    return result;
}

ClassList(obj);

 
function ClassList(collection = {}) {    const result = {};​    function flatten(node, str) {        const nodeType = Object.prototype.toString.call(node);                switch (nodeType) {            case '[object String]': {                str += node + ' ';                break;            }            case '[object Array]': {                str += node.join(' ') + ' ';                break;            }            case '[object Object]': {                for (const key in node) {                    str += flatten(node[key], '');                }                break;            }        }                return str;    }​    for (const key in collection) {        result[key] = flatten(collection[key], '').trimEnd();    }​    return result;}​ClassList(obj);