Is there a way to simplify this code with the use of Object.entries()? I want to remove new Map().
const err = [{
'id': 1,
'error': ["Error 1", "Error2"]
}]
const warn = [{
'id': 1,
'warning': ["Warn 1", "Warn 2"]
}]
const map = new Map();
err.forEach(item=> map.set(item.id, item));
warn.forEach(item=> map.set(item.id, {...map.get(item.id), ...item}));
const combined = Array.from(map.values());
console.log(combined)
Tried:
const map = new Map(Object.entries(err));
warn.forEach(item=> map.set(item.id, {...map.get(item.id), ...item}));
const combined = Array.from(map.values());
console.log(combined)
The output should still be the same
[{
'id': 1,
'error': ["Error 1", "Error2"],
'warning': ["Warn 1", "Warn 2"]
}]
You can use Array.prototype.map() to create the key/value pairs for the new Map() argument.
const err = [{
'id': 1,
'error': ["Error 1", "Error 2"]
}]
const warn = [{
'id': 1,
'warning': ["Warn 1", "Warn 2"]
}]
const map = new Map(err.map(el => [el.id, el]));
warn.forEach(el => map.get(el.id).warning = el.warning);
const combined = Array.from(map.values());
console.log(combined)Object.entries() isn't useful because the keys are the array indexes, not the id properties.If you expect more than 1 item per array you can do:
const err = [{
'id': 1,
'error': ["Error 1", "Error2"]
}]
const warn = [{
'id': 1,
'warning': ["Warn 1", "Warn 2"]
}]
const newObj = err.map( (item,i) => Object.assign({},item,warn[i]));
console.log(newObj)If the final object depends on those other arrays and you know in advance that they have exactly length 1 then is simpler:
const err = [{
'id': 1,
'error': ["Error 1", "Error2"]
}]
const warn = [{
'id': 1,
'warning': ["Warn 1", "Warn 2"]
}]
const newArr = [Object.assign({},err[0],warn[0])]
console.log(newArr)Object entries is for object, not an array. However you can group by using reduce
into object, then get his values to turn into array.
const err = [{
'id': 1,
'error': ["Error 1", "Error 2"]
}]
const warn = [{
'id': 1,
'warning': ["Warn 1", "Warn 2"]
}]
var combined = Object.values(err.concat(warn).reduce(function(agg, item) {
agg[item.id] = { ...agg[item.id], ...item}
return agg;
}, {}));
console.log(combined)