As the title states, I am trying to return an array containing the value associated with that key for each object, or undefined if that key is not present.
Here is what I have so far:
function pluck(arr, name) {
permittedValues = arr.map(function(value) {
return value.key || undefined;
});
}
console.log(
pluck([
{ name: "Tim" }, { name: "Matt" }, { name: "Elie" }],
'name'
)
);I am trying to return something like this:
// ["Tim", "Matt", "Elie"]
You can use indexer to get the property and if it doesn't exist, undefined will be returned:
function pluck(arr, name) {
return arr.map(function (value) {
return value[name];
});
}
You don't need to return value[name] || undefined, if name key doesn't exist it will return undefined anyway.
function pluck(arr, name) {
return permittedValues = arr.map(value =>
value[name]);
}
console.log(
pluck([
{ name: "Tim" }, { name: "Matt" }, { name: "Elie" }],
'name'
)
);This code can get even more concise using arrow functions
const pluck = (arr, name) => arr.map(value => value[name])
console.log(pluck([{ name: "Tim" }, { name: "Matt" }, { name: "Elie" }],'name'));
value[name]would be the array syntaxvalue.keyis the property namedkey, not the property named whatever the value ofkeyis. See e.g. stackoverflow.com/q/4841254/3001761.key. Did you mean to writefunction pluck(arr, key)?