I was hoping this work, but it didn't:
var myName = _(myArray)
.find({ "ID": 5 })
.get("Name");
Basically I want to find one element within an array, where ID property is equal to 5 and then get value of "Name" property of that.
What am I missing ?
You don't need to use .get() here. .find() returns the matching object, so to pull its Name property you can simply reference .Name on that object:
var myName = _(myArray).find({ "ID": 5 }).Name;
This will only work if the .find() call succeeds. You may want to store the result of the .find() in a variable, then check if that isn't null before returning the Name property:
var match = _(myArray).find({ "ID": 5 }),
myName;
if (match) {
myName = match.Name;
}
get() can be a good substitute for if statements that check for a match, and intermediary variables. For instance, var myName = _.get(_.find(myArray, { ID: 5 }), 'Name');.Below, I have written three different calls which will all return the desired data. As they say, there is more than one way to skin a cat, when it comes to programming. You must choose the most effective or efficient for your needs.
The two latter function below, which uses the _.result function, have been adapted from the lodash documentation. You can use result as a replacement for _.get().
_.result(object, path, [defaultValue])This method is like
_.getexcept that if the resolved value is a function it’s invoked with the this binding of its parent object and its result is returned.Arguments
object(Object): The object to query.path(Array|string): The path of the property to resolve.[defaultValue](*): The value returned if the resolved value is undefined.Returns
- (*): Returns the resolved value.
var myArray = [
{ ID : 0, Name : 'Foo' },
{ ID : 1, Name : 'Bar' },
{ ID : 5, Name : 'Baz' },
{ ID : 10, Name : 'Oof' }
];
// Convienience function to print to the DOM. (Only for debugging)
function print() {
document.body.innerHTML += '<p>' + [].join.call(arguments, ' ') + '</p>';
}
// Find item using chaining with `_.find()` and `_.get()`.
print(
'<span class="lbl">Chain + Find + Get:</span>',
_(myArray).chain().find({ 'ID' : 5 }).get('Name')
);
// Find item using a predicate (function).
print(
'<span class="lbl">Find (Function Predicate) + Result:</span>',
_.result(_.find(myArray, function(chr) {
return chr.ID === 5;
}), 'Name')
);
// Find item using the `_.matches()` callback shorthand.
print(
'<span class="lbl">Find (Object Predicate) + Result:</span>',
_.result(_.find(myArray, { 'ID' : 5 }), 'Name')
);.lbl {
font-weight: bold;
}<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/3.10.1/lodash.js"></script>
Object does not support 'get' property