I have an Object array looks like this:
const myArray = [
{ bet_line: "1",bet_type: 1, f1: true, f2: true, f3: true, f4: false, f5:false }
{ bet_line: "1",bet_type: 2, f1: false, f2: true, f3: true, f4: true, f5:false }
{ bet_line: "1",bet_type: 4, f1: true, f2: false, f3: true, f4: true, f5:false }
... ...
];
and What i want to get is:
const chartData = [
{name:'F1', value:2},
{name:'F2', value:2},
{name:'F3', value:3},
{name:'F4', value:2},
{name:'F5', value:0}
];
Now, I know how to get each element of new array by using array function:
const f1 = myArray.filter((x,i) => { return x.f1; }).length
const f2 = myArray.filter((x,i) => { return x.f1; }).length
...
Actually there are more than 5 for F* element, like F1~F20, so to caculuate everytime is not suitable way. I want to find more simple way, Is there any way to do this by using Javascript Array function?
You can use a single reduce to "sum" the items. Because they're booleans, it's safe (in javascript...) to sum them using +:
const myArray = [
{ bet_line: "1",bet_type: 1, f1: true, f2: true, f3: true, f4: false, f5:false },
{ bet_line: "1",bet_type: 2, f1: false, f2: true, f3: true, f4: true, f5:false },
{ bet_line: "1",bet_type: 4, f1: true, f2: false, f3: true, f4: true, f5:false }
];
const sumBet = (b1, b2) => ({ f1: b1.f1 + b2.f1, f2: b1.f2 + b2.f2, f3: b1.f3 + b2.f3, f4: b1.f4 + b2.f4, f5: b1.f5 + b2.f5 });
const emptyBet = () => ({ f1: false, f2: false, f3: false, f4: false, f5: false });
console.log(
myArray.reduce(sumBet, emptyBet())
)If you want it to be more generic, you can extract the key definition:
const myArray = [
{ bet_line: "1",bet_type: 1, f1: true, f2: true, f3: true, f4: false, f5:false },
{ bet_line: "1",bet_type: 2, f1: false, f2: true, f3: true, f4: true, f5:false },
{ bet_line: "1",bet_type: 4, f1: true, f2: false, f3: true, f4: true, f5:false }
];
const sumKeys = ks => (a, b) => Object.fromEntries(ks.map(k => [k, a[k] + b[k]]));
const constKeys = (ks, c) => Object.fromEntries(ks.map(k => [k, c]));
const keys = Array.from(Array(5), (_, i) => `f${i + 1}`);
console.log(
myArray.reduce(sumKeys(keys), constKeys(keys, 0))
)