I have an array of values similar to:
["100", "330", "22", "100", "4.7", "0.01", "0.01", "330", "0.01", "100", "47", "22", "100", "0.01"]
Using JavaScript I would like to split this array into a number of arrays where only matching strings are in those arrays like this:
["100", "100", "100"]
["330", "330"]
["22", "22"]
["0.01", "0.01", "0.01", "0.01"]
["47"]
["4.7"]
Any help with this would be much appreciated! Thanks!
You could collect with a Map and get the values as result.
From inside out:
Array#reduce with data and use a Map instance as initialValue.Map#set and collect the values for each group.Further methods:
spread syntax ... for getting all items of an iterable together with
logical OR || for having a default value for spreading.
Get the values from the map and use it as parameter for
Array.from. This generates an array of all values.
var data = ["100", "330", "22", "100", "4.7", "0.01", "0.01", "330", "0.01", "100", "47", "22", "100", "0.01"],
result = Array.from(data
.reduce((m, v) => m.set(v, [...m.get(v) || [], v]), new Map)
.values()
);
console.log(result);.as-console-wrapper { max-height: 100% !important; top: 0; }
Use reduce method and Object.values
//Go thru each value in `arr` array and convert into object with
//keys as unique (value in array) and values array of value repetitions.
{
"100": ["100", "100"],
"22": ["22"],
...
...
}
//Use the Object.values to get the Values as array of arrays
const arr = ["100", "330", "22", "100", "4.7", "0.01", "0.01",
"330", "0.01", "100", "47", "22", "100","0.01"];
const updated = Object.values(
arr.reduce(
(acc, curr) => (
(acc[curr] = curr in acc ? [...acc[curr], curr] : [curr]), acc
),
{}
)
);
console.log(updated);
Here's another take on using reduce to group by the values.
It reduces to an object, which is then transformed to an array of arrays.
let valueArray = ["100", "330", "22", "100", "4.7", "0.01", "0.01", "330", "0.01", "100", "47", "22", "100", "0.01"];
let groupedByValue = Object.values(valueArray
.reduce((acc, x)=>{
let arr = acc[x] || [];
arr.push(x);
acc[x] = arr;
return acc;
},{}));
console.log(groupedByValue);Extra
Here's a version that will group the unique values by the same format.
It was something cooked up when this question was originally completely misunderstood by yours truly. (it happens...)
let valueArray = ["100", "330", "22", "102", "4.7", "0.01", "0.02", "330", "0.01", "101", "47", "23", "100", "0.02"];
let groupedByFormat = Object.values(valueArray
.reduce((acc, x)=>{
let val = x.trim();
let format = val.replace(/\d/g,'0');
let arr = acc[format] || [];
if(!arr.includes(val)) {
arr.push(val);
acc[format] = arr.sort();
}
return acc;
},{}));
console.log(groupedByFormat);Also it can be done like this:
const {log} = console;
const arr = ["100", "330", "22", "100", "4.7", "0.01", "0.01", "330", "0.01", "100", "47", "22", "100", "0.01"];
log([...new Set(arr)].map( x => arr.filter( y => y === x )));
Here's an example of what you want using Set.
const data = ["100", "330", "22", "100", "4.7", "0.01", "0.01", "330", "0.01", "100", "47", "22", "100", "0.01"];
const unique = new Set(data);
for(let num of unique) {
console.log(data.filter(d => d == num));
}
"0.01, "330", 0.01"