Why reinvent the wheel? Give Lodash a try. It has a number of must-have functions such as isEqual(). _.isEqual(object, other); It will brute force check each key value – just like the other examples on this page – using ECMAScript 5 and native optimizations if they’re available in the browser. Note: Previously this answer recommended Underscore.js, … Read more
ECMAScript 6 introduces the easily polyfillable Object.assign: The Object.assign() method is used to copy the values of all enumerable own properties from one or more source objects to a target object. It will return the target object. Object.assign({}, [‘a’,’b’,’c’]); // {0:”a”, 1:”b”, 2:”c”} The own length property of the array is not copied because it … Read more
Try hasattr(): if hasattr(a, ‘property’): a.property See zweiterlinde’s answer below, who offers good advice about asking forgiveness! A very pythonic approach! The general practice in python is that, if the property is likely to be there most of the time, simply call it and either let the exception propagate, or trap it with a try/except … Read more
you can also use Array.some() function: const arr = [ { id: 19, cost: 400, name: ‘Arkansas’, height: 198, weight: 35 }, { id: 21, cost: 250, name: ‘Blofeld’, height: 216, weight: 54 }, { id: 38, cost: 450, name: ‘Gollum’, height: 147, weight: 22 } ]; console.log(arr.some(item => item.name === ‘Blofeld’)); console.log(arr.some(item => item.name … Read more
While the other answers are true, there is a new technique in C++11 for expressing that : deleted default constructor It allows forbidding a function without depending on any other trick. It also clearly express your intention in the code. class X { public: X(int) {} X() = delete; // will never be generated }; … Read more
a) What’s wrong with a simple a.b[0].c=”After”? As for the method: function setToValue(obj, value, path) { var i; path = path.split(‘.’); for (i = 0; i < path.length – 1; i++) obj = obj[path[i]]; obj[path[i]] = value; } Here the JSFiddle: http://jsfiddle.net/QycBz/24/
You can use any key if you use [string] to access the key, even key with space. All of these are valid: myObj[‘key with space’] myObj[‘12345’] But if you want to use dot . operator to access the key then the key must be a valid identifier which means they can not begin with a … Read more
Well, they’re not exactly comparable. You will always have to create a new object by instantiating a class at some point. Dependency injection also requires creating new objects. Dependency injection really comes into play when you want to control or verify the behavior of instances used by a class that you use or want to … Read more
In ES6/ ES2015 you can use the Object.assign method let obj = {key1: true}; console.log(‘old obj: ‘, obj); let newObj = {key2: false, key3: false}; Object.assign(obj, newObj); console.log(‘modified obj: ‘, obj);