TheObject.keys()method# TheObject.keys()method returns an array of keys from an object. You pass in the object as an argument. // logs ["sandwich", "chips", "drink"]letkeys=Object.keys(lunch);console.log(keys); You can combine it with afor...ofloop (or any of the other array...
For loop example over an iterable object In the following example, we’re looping over the variableobjand logging each property and value: constobj={"a":"JavaScript",1:"PHP","b":"Python",2:"Java"};for(letkeyinobj){console.log(key+": "+obj[key])}// Output:// "1: PHP"// "...
-1:100*e}（2）连等连等是利用赋值运算表达式会返回所赋的值，并且执行顺序是从右到左的，如下：o...
Looping over a String Example letlanguage ="JavaScript"; lettext =""; for(letx of language) { text += x +" "; } Try it Yourself » Learn more in the chapter:JavaScript Loop For/In/Of. JavaScript Maps Being able to use an Object as a key is an important Map feature. ...
EnhancedForLoop: a “for-in” or “for-of” loop; use EnhancedForLoop.getIterator() to access the loop iterator (which may be a expression or variable declaration), and EnhancedForLoop.getIterationDomain() to access the expression being iterated over. ForInStmt, ForOfStmt: a “for-in”...
The keys before, after, beforeEach, and afterEach are special-cased, object values are suites, and function values are test-cases: module.exports = { before: function() { // ... }, Array: { '#indexOf()': { 'should return -1 when not present': function() { [1, 2, 3].index...
In our case, we simply log the number of announcements of true and false to the console:const render = state => { const numberBeliefsTrue = Object.keys(state).filter( agentId => state[agentId].keyBelief ).length const numberBeliefsFalse = Object.keys(state).filter( agentId => !state[...
objects (default: true)— compact duplicate keys in object literals. passes (default: 1)— The maximum number of times to run compress. In some cases more than one pass leads to further compressed code. Keep in mind more passes will take more time. properties (default: true)— rewrite pro...
The goToMedia() method in the Feature widget and its corresponding viewModel has been renamed to setActiveMedia. The tables property for WebMap now takes a collection of Layers instead of an array of Objects. The TimeSlider.loop property now has a default value of false instead of true. Serv...
Indicates whether the layer will be included in the legend. WMSLayer listMode String Indicates how the layer should display in the LayerList widget. Layer loadError Error|null|undefined The Error object returned if an error occurred while loading. Layer loadStatus String Represents the status of ...