一尘不染

在Node.js中使用Underscore模块

node.js

我一直在学习有关node.js和模块的信息,似乎无法让Underscore库正常工作……似乎我第一次使用Underscore中的函数时,它会覆盖_对象,其结果为我的函数调用。有人知道发生了什么吗?例如,这是来自node.js
REPL的会话:

Admin-MacBook-Pro:test admin$ node
> require("./underscore-min")
{ [Function]
  _: [Circular],
  VERSION: '1.1.4',
  forEach: [Function],
  each: [Function],
  map: [Function],
  inject: [Function],
  (...more functions...)
  templateSettings: { evaluate: /<%([\s\S]+?)%>/g, interpolate: /<%=([\s\S]+?)%>/g },
  template: [Function] }
> _.max([1,2,3])
3
> _.max([4,5,6])
TypeError: Object 3 has no method 'max'
    at [object Context]:1:3
    at Interface.<anonymous> (repl.js:171:22)
    at Interface.emit (events.js:64:17)
    at Interface._onLine (readline.js:153:10)
    at Interface._line (readline.js:408:8)
    at Interface._ttyWrite (readline.js:585:14)
    at ReadStream.<anonymous> (readline.js:73:12)
    at ReadStream.emit (events.js:81:20)
    at ReadStream._emitKey (tty_posix.js:307:10)
    at ReadStream.onData (tty_posix.js:70:12)
> _
3

当我自己制作Javascript文件并将其导入时,它们似乎工作正常。Underscore库也许有一些特别之处?


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2020-07-07

共1个答案

一尘不染

Node REPL使用underscore变量保存上一次操作的结果,因此它与Underscore库对同一变量的使用相冲突。尝试这样的事情:

Admin-MacBook-Pro:test admin$ node
> _und = require("./underscore-min")
{ [Function]
  _: [Circular],
  VERSION: '1.1.4',
  forEach: [Function],
  each: [Function],
  map: [Function],
  inject: [Function],
  (...more functions...)
  templateSettings: { evaluate: /<%([\s\S]+?)%>/g, interpolate: /<%=([\s\S]+?)%>/g },
  template: [Function] }
> _und.max([1,2,3])
3
> _und.max([4,5,6])
6
2020-07-07