function convert(data){
var myMap = {}
data.forEach(el => myMap[el] = myMap[el] != undefined ? myMap[el] + 1 : 1);
return Object.keys(myMap).map(k => {return {name: k, y: myMap[k]}})
}
console.log(convert(['A','B','B','B','C','C','A','B']))
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solved JavaScript array to dictionary conversation based on count