You didn’t ask for how to do it, but I assume that’s what you wanted to know. As I already mentioned, you can use _.some, which will iterate over every element in the array and execute a callback. In that callback you can test whether the value of the topic’s property equals the value of … Read more
Typescript isn’t discarding type information here. In the DefinitelyTyped lodash.d.ts file, you can see that cloneDeep is defined as cloneDeep<T>( val: T, customizer?: (value: any) => any, thisArg?: any ) : T Ignoring the arguments we don’t care about, it takes a T as input, and spits out a T as output. So Typescript isn’t … Read more
Why all people gets over-complicated here? const people = [ { name: ‘Alejandro’, budget: 56 }, { name: ‘Juan’, budget: 86 }, { name: ‘Pedro’, budget: 99 }, ]; const average = _.meanBy(people, (p) => p.budget); console.log(average); <script src=”https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.15/lodash.min.js”></script> As per the docs: https://lodash.com/docs/#meanBy
Update: See the comments below, this is not a good solution in most cases. Someone kindly answered in the issue I created. Here’s his answer, inlined: _.sortBy(data, function(item) { return [item.sortData.a, item.sortData.b]; }); I didn’t realize that you’re allowed to return an array from that function. The documentation doesn’t mention that.
You could use reduce again to achieve that in plain JavaScript: var filtered = Object.keys(dict).reduce(function (filtered, key) { if (dict[key] > 1) filtered[key] = dict[key]; return filtered; }, {}); With some ES6 features, such as arrow functions, spread syntax, Object.entries, … it can look like this: var filtered = Object.assign({}, … Object.entries(dict).filter(([k,v]) => v>1).map(([k,v]) => … Read more
You can use Array.prototype.find() with pure javascript: var picked = arr.find(o => o.city === ‘Amsterdam’); It is currently not compatible with all browsers, you need to check it in your environment (but it should work in NodeJS).
One can use apply to pass an arbitrary number of arguments to a method. For union: // Outputs [1, 4, 5, 6, 2, 3, 7] var selectedUnion = _.union.apply(_, selected); For intersection: // Outputs [1] var selectedIntersection = _.intersection.apply(_, selected);
Here are two vanilla javascript options: A.: Iterate over the object’s keys and delete those having a falsey value. var obj = { propA: true, propB: true, propC: false, propD: true, }; Object.keys(obj).forEach(key => { if (!obj[key]) delete obj[key]; }); console.log(obj); See Object.keys() and Array.prototype.forEach() B.: Iterate over the object’s keys and add truthy values … Read more
You can make use of differenceWith() with an isEqual() comparator, and invoke isEmpty to check if they are equal or not. var isArrayEqual = function(x, y) { return _(x).differenceWith(y, _.isEqual).isEmpty(); }; var result1 = isArrayEqual( [{a:1, b:2}, {c:3, d:4}], [{b:2, a:1}, {d:4, c:3}] ); var result2 = isArrayEqual( [{a:1, b:2, c: 1}, {c:3, d:4}], [{b:2, … Read more
You can try this code: function hasDuplicates(a) { return _.uniq(a).length !== a.length; } var a = [1,2,1,3,4,5]; var b = [1,2,3,4,5,6]; document.write(hasDuplicates(a), ‘,’,hasDuplicates(b)); <script src=”http://cdnjs.cloudflare.com/ajax/libs/lodash.js/3.1.0/lodash.min.js”></script>