### object.selectors
> Functions to select values from an object.
——————————————————————————–
#### accessor
**Signature:** `_.accessor(field:String)`
Returns a function that will attempt to look up a named field in any object
that it is given.
“`javascript
var getName = _.accessor(‘name’);
getName({ name: ‘Seneca’ });
// => ‘Seneca’
“`
——————————————————————————–
#### dictionary
**Signature:** `_.dictionary(obj:Object)`
Given an object, returns a function that will attempt to look up a field that
it is given.
“`javascript
var generals = {
rome: “Scipio”,
carthage: “Hannibal”
};
var getGeneralOf = _.dictionary(generals);
_.getGeneralOf(“rome”);
// => “Scipio”
“`
——————————————————————————–
#### getPath
**Signature:** `_.getPath(obj:Object, ks:String|Array)`
Gets the value at any depth in a nested object based on the path described by
the keys given. Keys may be given as an array or as a dot-separated string.
Returns `undefined` if the path cannot be reached.
“`javascript
var countries = {
greece: {
athens: {
playwright: “Sophocles”
}
}
}
};
_.getPath(countries, “greece.athens.playwright”);
// => “Sophocles”
_.getPath(countries, “greece.sparta.playwright”);
// => undefined
_.getPath(countries, [“greece”, “athens”, “playwright”]);
// => “Sophocles”
_.getPath(countries, [“greece”, “sparta”, “playwright”]);
// => undefined
“`
——————————————————————————–
#### hasPath
**Signature:** `_.hasPath(obj:Object, ks:String|Array)`
Returns a boolean indicating whether there is a property at the path described
by the keys given. Keys may be given as an array or as a dot-separated string.
“`javascript
var countries = {
greece: {
athens: {
playwright: “Sophocles”
}
}
}
};
_.hasPath(countries, “greece.athens.playwright”);
// => true
_.hasPath(countries, “greece.sparta.playwright”);
// => false
_.hasPath(countries, [“greece”, “athens”, “playwright”]);
// => true
_.hasPath(countries, [“greece”, “sparta”, “playwright”]);
// => false
“`
——————————————————————————–
#### kv
**Signature:** `_.kv(obj:Object, key:String)`
Returns the key/value pair for a given property in an object, undefined if not found.
“`javascript
var playAuthor = {
“Medea”: “Aeschylus”
};
_.kv(playAuthor, “Medea”);
// => [“Medea”, “Aeschylus”]
_.kv(playAuthor, “Hamlet”);
// => undefined
“`
——————————————————————————–
#### omitWhen
**Signature:** `_.omitWhen(obj, pred:Function)`
Returns a copy of `obj` omitting any properties that the predicate (`pred`)
function returns `true` for. The predicat function is invoked with each
property value, like so: `pred(propValue)`.
“`javascript
var playwrights = {
euripedes: “Greece”,
shakespere: “England”
};
_.omitWhen(obj, function (country) { return country == “England” });
// => { euripedes: “Greece” }
“`
——————————————————————————–
#### pickWhen
**Signature:** `_.pickWhen(obj:Object, pred:Function)`
Returns a copy of `obj` containing only properties that the predicate (`pred`)
function returns `true` for. The predicate function is invoked with each
property value, like so: `pred(propValue)`.
“`javascript
var playwrights = {
euripedes: “Greece”,
shakespere: “England”
};
_.pickWhen(obj, function (country) { return country == “England” });
// => { shakespeare: “England” }
“`
——————————————————————————–
#### selectKeys
**Signature:** `_.selectKeys(obj:Object, ks:Array);
Returns a copy of `obj` containing only the properties listed in the `ks` array.
“`javascript
var philosopherCities = {
Philo: “Alexandria”,
Plato: “Athens”,
Plotinus: “Rome”
}
_.selectKeys(philosopherCities, [“Plato”, “Plotinus”]);
// => { Plato: “Athens”, Plotinus: “Rome” }
“`