arrow-functions

问题 Hello friends! I hope you are well. I've got an arrow function called WorldInfo and its parent component is passing down an object in props that for the sake of this example, I'm just calling object . Now In WorldInfo I also want to parse and list the items in object , so I've created the method serverInfoTabList to take object and shove it through .map . My problem is when compiled, my browser does not recognize serverInfoTabList either when it's defined nor called in WorldInfo 's own return

问题 Hello friends! I hope you are well. I've got an arrow function called WorldInfo and its parent component is passing down an object in props that for the sake of this example, I'm just calling object . Now In WorldInfo I also want to parse and list the items in object , so I've created the method serverInfoTabList to take object and shove it through .map . My problem is when compiled, my browser does not recognize serverInfoTabList either when it's defined nor called in WorldInfo 's own return

问题 So we can do: export function myMethod (param: number) :number export function myMethod (param: string) :string export function myMethod (param: string | number): string | number { if (typeof param === 'string') { return param.toUpperCase() } else { return param + 1 } } Can I declare and implement it with arrow function? export var myMethodArror = (param: string): string export var myMethodArror = (param: number): number export var myMethodArror = (param: string | number): string | number =>

问题 Arrow functions in ES6 do not have an arguments property and therefore arguments.callee will not work and would anyway not work in strict mode even if just an anonymous function was being used. Arrow functions cannot be named, so the named functional expression trick can not be used. So... How does one write a recursive arrow function? That is an arrow function that recursively calls itself based on certain conditions and so on of-course? 回答1: Writing a recursive function without naming it is

问题 Arrow functions in ES6 do not have an arguments property and therefore arguments.callee will not work and would anyway not work in strict mode even if just an anonymous function was being used. Arrow functions cannot be named, so the named functional expression trick can not be used. So... How does one write a recursive arrow function? That is an arrow function that recursively calls itself based on certain conditions and so on of-course? 回答1: Writing a recursive function without naming it is

问题 Arrow functions in ES6 do not have an arguments property and therefore arguments.callee will not work and would anyway not work in strict mode even if just an anonymous function was being used. Arrow functions cannot be named, so the named functional expression trick can not be used. So... How does one write a recursive arrow function? That is an arrow function that recursively calls itself based on certain conditions and so on of-course? 回答1: Writing a recursive function without naming it is

问题 I have been trying to understand es6 arrow function. I read some articles introducing it. But I'am still not getting it fully. For example I have this code: sortedArticles(): Article[] { return this.articles.sort((a: Article, b: Article) => b.votes - a.votes); } It sorts the below array: [ new Article('Angular 2', 'http://angular.io', 3), new Article('Fullstack', 'http://fullstack.io', 2), new Article('Angular Homepage', 'http://angular.io', 1), ]; How would the same code look in plain old js

问题 (() => console.log(arguments))(1,2,3); // Chrome, FF, Node give "1,2,3" // Babel gives "arguments is not defined" from parent scope According to Babel (and from what I can tell initial TC39 recommendations), that is "invalid" as arrow functions should be using their parent scope for arguments. The only info I've been able to find that contradicts this is a single comment saying this was rejected by TC39, but I can't find anything to back this up. Just looking for official docs here. 回答1:

问题 (() => console.log(arguments))(1,2,3); // Chrome, FF, Node give "1,2,3" // Babel gives "arguments is not defined" from parent scope According to Babel (and from what I can tell initial TC39 recommendations), that is "invalid" as arrow functions should be using their parent scope for arguments. The only info I've been able to find that contradicts this is a single comment saying this was rejected by TC39, but I can't find anything to back this up. Just looking for official docs here. 回答1:

问题 This question already has answers here : Filter array of objects by multiple properties and values (3 answers) Closed 11 months ago . Suppose I have an array like: const items=[{ "taskType": "type2", "taskName": "two", "id": "19d0da63-dfd0-4c00-a13a-cc822fc81298" }, { "taskType": "type1", "taskName": "two", "id": "c5385595-2104-409d-a676-c1b57346f63e" }] I want to have an arrow (filter) function that returns all items except for where taskType=type2 and taskName=two. So in this case it just