consider the following sample JS Object
const samplejson = [
{id:'1',value: "AC",},
{id:'2',value: "AB",},
{id:'3',value: "AC",},
{id:'4',value: "AA",},
{id:'5',value: "AA",},
{id:'6',value: "AA",},
{id:'7',value: "AB",},
{id:'8',value: "AC",},
{id:'9',value: "AA",},
{id:'10',value: "AA",},
]
I want to filter the JS object based on the values unique count and descending order like the following
based on the value counts AA - 5, AB - 2 and AC - 3, but I need the output as AA,AC
In react or JS how can achieve this?
Check this out:
const data = [{id:'1',value: "AC",},{id:'2',value: "AB",},{id:'3',value: "AC",}, {id:'4',value: "AA",},{id:'5',value: "AA",},{id:'6',value: "AA",},{id:'7',value: "AB",}, {id:'8',value: "AC",},{id:'9',value: "AA",},{id:'10',value: "AA",},];
const result = Object.entries(
data.reduce((acc, { value }) => ({ ...acc, [value]: (acc[value] || 0) + 1 }), {})
).sort((a1, a2) => a2[1] - a1[1])
.map(([key]) => key)
.join(',');
console.log(result);You could iterate over any key in the sample data and count each occurrence of a value in a dictionary. Then you can both print the dictionary for a list of amount of occurrences or just the amount of occurrences of one value.
const data = [
{id:'1',value: "AC",},
{id:'2',value: "AB",},
{id:'3',value: "AC",},
{id:'4',value: "AA",},
{id:'5',value: "AA",},
{id:'6',value: "AA",},
{id:'7',value: "AB",},
{id:'8',value: "AC",},
{id:'9',value: "AA",},
{id:'10',value: "AA",},
]
// make a dict to store and count occurrences
dict = {};
//iterate over every key in your data and keep count in dict
//(initializing it to 1 if it not exists yet)
for(let i = 0; i < data.length; i++){
value = data[i].value;
if(value in dict){
dict[value]++;
}else{
dict[value] = 1;
}
}
// here the amount of occurrences are know
console.log(dict);
amountOfAA = dict['AA'];
Output: { AC: 3, AB: 2, AA: 5 } 5
Your desired result can be found using the following steps:
const items = [
{ id: '1', value: "AC" },
{ id: '2', value: "AB" },
{ id: '3', value: "AC" },
{ id: '4', value: "AA" },
{ id: '5', value: "AA" },
{ id: '6', value: "AA" },
{ id: '7', value: "AB" },
{ id: '8', value: "AC" },
{ id: '9', value: "AA" },
{ id: '10', value: "AA" },
];
const tally = new Map();
for (const { value } of items) {
if (!tally.has(value)) tally.set(value, 0);
tally.set(value, tally.get(value) + 1);
}
// displaying as object because Map instances show empty in the snippet log
console.log(Object.fromEntries(tally));
const results = Array.from(tally)
.sort(([,countA], [,countB]) => countB - countA)
.map(([value]) => value);
console.log(results);