This is probably an easy question but I haven't been able to find an answer from the lodash API docs and Google.
Let's assume I have an object like this:
var obj = {
code: 2,
persistence: true
}
I want a function that I can pass a key/value pair and returns true if the key exists in my object and has the specified value:
_.XXXX(obj, {code: 2}); //true
_.XXXX(obj, {code: 3}); //false
_.XXXX(obj, {code: 2, persistence: false}); //false
_.XXXX(obj, {code: 2, persistence: true}); //true
This is somehow like where()
but for only one object.
You could use a matcher :
var result1 = _.matcher({ code: 2 })( obj ); // returns true
var result2 = _.matcher({ code: 3 })( obj ); // returns false
with a mixin:
_.mixin( { keyvaluematch: function(obj, test){
return _.matcher(test)(obj);
}});
var result1 = _.keyvaluematch(obj, { code: 2 }); // returns true
var result2 = _.keyvaluematch(obj, { code: 3 }); // returns false
Edit
Version 1.8 of underscore added an _.isMatch function.
var obj = {
code: 2,
persistence: true
};
console.log(_.has(obj, 'code'));
My bad for misunderstanding your requirement at first.
Here's the corrected answer with _.some
https://lodash.com/docs#some
var obj = {
code: 2,
persistence: true
};
console.log( _.some([obj], {code: 2}) );
console.log( _.some([obj], {code: 3}) );
console.log( _.some([obj], {code: 2, persistence: false}) );
console.log( _.some([obj], {code: 2, persistence: true}) );
The trick is to cast the object you want to check as an Array so that _.some
will do its magic.
If you want a nicer wrapper instead of having to manually cast it with []
, we can write a function that wraps the casting.
var checkTruth = function(obj, keyValueCheck) {
return _.some([obj], keyValueCheck);
};
console.log( checkTruth(obj, {code: 2}) );
... as above, just using the `checkTruth` function now ...
I don't think there is one single underscore function for that, but you can easily write one:
function sameObject(ob1, ob2) {
for (var key in ob2) {
if (ob2[key] != ob1[key]) {
return false;
}
}
return true;
}
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