意外的令牌=节点8.4中的类属性

在节点（v8.4）中运行以下代码

class TodoStore { todos = []; get completedTodosCount() { return this.todos.filter( todo => todo.completed === true ).length; } report() { if (this.todos.length === 0) return "<none>"; return `Next todo: "${this.todos[0].task}". ` + `Progress: ${this.completedTodosCount}/${this.todos.length}`; } addTodo(task) { this.todos.push({ task: task, completed: false, assignee: null }); } } const todoStore = new TodoStore(); todoStore.addTodo("read MobX tutorial"); console.log(todoStore.report()); todoStore.addTodo("try MobX"); console.log(todoStore.report()); todoStore.todos[0].completed = true; console.log(todoStore.report()); todoStore.todos[1].task = "try MobX in own project"; console.log(todoStore.report()); todoStore.todos[0].task = "grok MobX tutorial"; console.log(todoStore.report()); 

给我以下错误：

  todos = []; ^ SyntaxError: Unexpected token = at createScript (vm.js:74:10) at Object.runInThisContext (vm.js:116:10) at Module._compile (module.js:537:28) at Object.Module._extensions..js (module.js:584:10) at Module.load (module.js:507:32) at tryModuleLoad (module.js:470:12) at Function.Module._load (module.js:462:3) at Function.Module.runMain (module.js:609:10) at startup (bootstrap_node.js:158:16) at bootstrap_node.js:598:3 

Answer 1

根据这个表格 ，任何版本的节点都不支持Literal类属性。 实例属性，你必须在你的类的构造函数中设置它们：

 class TodoStore { constructor() { this.todos = []; } // ... } 

如果你想定义一个静态属性，你可以在声明该类之后直接把它分配给TodoStore引用：

 TodoStore.todos = [];