I have an array of objects with different values in it, I want to find the min, max, and average of the properties in that array
for eg if I have an array
const array = [{
"a": "-0.06",
"b": "0.25",
"c": "-0.96",
"d": "-0.14"
},
{
"a": "-0.37",
"b": "0.01",
"c": "-0.77",
"d": "-0.09"
},
{
"a": "0.01",
"b": "0.88",
"c": "-0.53",
"d": "-0.28"
},
{
"a": "0.53",
"b": "-0.62",
"c": "0.02",
"d": "0.74"
},
{
"a": "0.79",
"b": "-0.39",
"c": "0.70",
"d": "0.18"
},
{
"a": "0.74",
"b": "-0.14",
"c": "0.22",
"d": "-0.58"
}
]So the output will be as given below
const out = [{
property: a,
minValue: -0.37,
maxValue: .79,
avg: 0.2733333333333334
}, {
property: b,
minValue: -.62,
maxValue: .88,
avg: -0.0016666666666666496
}, {
property: c,
minValue: -.96,
maxValue: .07,
avg: -0.21999999999999997
}, {
property: d,
minValue: -.58,
maxValue: .74,
avg: -0.028333333333333332
}]So to get the output we iterate to the array and find the minimum, maximum, and average value of a, b , c and d and store it in a new array
here is a two step approach. First i grouped the array on property using reduce. Then I performed a map on the grouped object to get the min, max and the average
const array = [{ "a": "-0.06", "b": "0.25", "c": "-0.96", "d": "-0.14" }, { "a": "-0.37", "b": "0.01", "c": "-0.77", "d": "-0.09" },{ "a": "0.01", "b": "0.88", "c": "-0.53", "d": "-0.28" }, { "a": "0.53", "b": "-0.62", "c": "0.02", "d": "0.74" }, { "a": "0.79", "b": "-0.39", "c": "0.70", "d": "0.18" }, { "a": "0.74", "b": "-0.14", "c": "0.22", "d": "-0.58" }]
const grouped = array.reduce((acc,curr) => {
Object.entries(curr).forEach(([property,v])=>{
acc[property] = acc[property] || []
acc[property].push(+v) //+ for convert to a number before pushing
})
return acc
},{})
const out = Object.entries(grouped).map(([property,v]) => {
return {
property,
minValue: Math.min(...v), // min of an array. v is the array of numbers
maxValue: Math.max(...v), //max of an array
avg: v.reduce((a, b) => a + b) / v.length //average of an array
}
})
console.log(out)Use the following function: `
const createNewObj = (previous, current) => ({
minValue: Math.min(previous, current,
maxValue: Math.max(previous, current,
total: previous + current,
length: previous.length + 1,
avg: (previous + current) / (previous.length + 1)
})
const default = {
minValue: 0,
maxValue: 0,
total: 0,
length: 0,
avg: 0
}
array.reduce((previous, current) => {
a: createNewObj(previous[a], current[a]),
b: createNewObj(previous[b], current[b]),
c: createNewObj(previous[c], current[c]),
d: createNewObj(previous[d], current[d])
}
, {
a: default,
b: default,
c: default,
d: default
})
`
I have followed a two step process -
reduce for this)const array = [{ "a": "-0.06", "b": "0.25", "c": "-0.96", "d": "-0.14" }, { "a": "-0.37", "b": "0.01", "c": "-0.77", "d": "-0.09" },{ "a": "0.01", "b": "0.88", "c": "-0.53", "d": "-0.28" }, { "a": "0.53", "b": "-0.62", "c": "0.02", "d": "0.74" }, { "a": "0.79", "b": "-0.39", "c": "0.70", "d": "0.18" }, { "a": "0.74", "b": "-0.14", "c": "0.22", "d": "-0.58" }]
const out = [];
const newObj = array.reduce((prevValue, currValue) => {
Object.keys(currValue).forEach((el) => {
if (prevValue[el]) {
prevValue[el].push(Number(currValue[el]));
} else {
prevValue[el] = [Number(currValue[el])];
}
});
return prevValue;
}, {});
Object.keys(newObj).forEach((el) => {
out.push({
property: el,
minValue: Math.min(...newObj[el]),
maxValue: Math.max(...newObj[el]),
avg: newObj[el].reduce((a, b) => a + b, 0) / newObj[el].length
});
});
console.log(out);