Take the following as an example
data = [
{ "date" : '2013-01-01', "value" : 45 },
{ "date" : '2013-02-01', "value" : 50 },
{ "date" : '2013-03-01', "value" : 55 },
{ "date" : '2013-04-01', "value" : 50 },
{ "date" : '2013-05-01', "value" : 45 },
{ "date" : '2013-06-01', "value" : 50 },
{ "date" : '2013-07-01', "value" : 50 },
{ "date" : '2013-08-01', "value" : 52 }
]
How to add new name:value pairs #
data.map(function(d) {
d.valuePlus = d.value + 1;
return d;
})
Or:
data.map(d => {
d.valuePlus = d.value + 1;
return d;
})
How to change names in the object’s name:value pairs #
This is basically to create a new object or a new array of objects
data.map(function(d) {return {
"newdate": d.date,
"newvalue": d.value,
}})
Or
data.map(d => ({
"newdate": d.date,
"newvalue": d.value,
}))
Note that in the second arrow function (right above), we use parentheses around object literals to let the function return “a single value”, which is an object.
We don’t need parenthese in the first arrow function because “curly braces are execuating multiple lines of codes”, quoting david .
Last modified on 2021-10-05