给定一个基本组件和一个自定义的handleChange()函数,“id”的参数在App.js中来自哪里?我知道所有事件函数都会接收一个事件属性作为参数,但是“id”是从哪里来的呢?这是否意味着我在给定的基于类的组件中编写的所有自定义函数都将接收事件参数之外的参数?
App.js组件
import React from "react"
import TodoItem from "./TodoItem"
import todosData from "./todosData"
class App extends React.Component {
在运行我的应用程序并试图路由到root/约时,我出现了这个错误
ReferenceError: Session is not defined at [object Object].route.onBeforeAction (app/lib/routes.js:38:8) at boundNext (packages/iron:middleware-stack/lib/middleware_stack.js:251:1) at runWithEnvironment (packages/meteor/dynamics_nodejs.js:108:1) at packages/meteor/dyna
我有一个包含以下内容的db.js文件
var mysql = require('mysql2');
var mysqlModel = require('mysql-model');
var appModel = mysqlModel.createConnection({
host : 'localhost',
user : 'root',
password : 'root',
database : 'tabio',
我有main.js
function someFunc($smt){
// Do something
}
require('./script.js');
当我尝试运行script.js时
someFunc($someParam);
我得到一个错误:
ReferenceError: someFunc is not defined
如何将父文件中的函数导入到请求文件中?
我正在用webpack和babel开发一个铬的扩展。
我有一个popup.js:
import 'regenerator-runtime/runtime' // This is required in every JS files that has an async-await function!!
const { NEW_MAPPING_BUTTON } = require('./constants/mapping-page-elements')
const gen_traffic = document.querySelector('.gen-tra
下面是一个NodeJS模块:
var plural = function(words, num) {
if (words.length != 3) {
throw new Error('Wrong words array');
}
var lastNum = num % 10;
var second = (num / 10) % 10;
if (second == 1)
return words[2]
else if (lastNum == 1)
return words[0];
我正在处理Node.js流,并在几个地方得到了这样的结果:
var myVariable = 'XXX';
...
.on('end', function() {
// do something with myVariable
});
函数的行为是相同的,但取决于一个变量,因此我想将其重构为:
var myVariable = 'XXX';
...
.on('end', myFunction);
function myFunction(param){
// do something with param
}
如