If I had an array of letters how would I go about turning each letter into an object key with a value of how many there are in that array in JavaScript?
For example:
const array = ['a', 'b', 'c', 'c', 'd', 'a'];
const obj = { a: 2, b: 1, c: 2, d: 1};
Objects can be indexed very similarly to arrays in JavaScript, like so:
const obj = {};
array.forEach((element) => {
//Check if that field exists on the object to avoid null pointer
if (!obj[element]) {
obj[element] = 1;
} else {
obj[element]++;
}
}
you can simply use Array.reduce() to create a frequency map :
const array = ['a', 'b', 'c', 'c', 'd', 'a'];
let result = array.reduce((a, curr) => {
a[curr] = (a[curr] || 0)+1;
return a;
},{});
console.log(result);
