NodeJs--process&util

全局对象

global

process

• process.argv
  命令行参数数组 node 文件名 运行参数

//argv.js
console.log(process.argv)
//cmd
$ node argv.js 123 name=zhang --v
[ 'C:\\Program Files\\nodejs\\node.exe',
  'E:\\atom-demo\\helloworld\\argv.js',
  '123',
  'name=zhang',
  '--v' ]

• process.stdout
  标准输出流，是比console.log的更底层实现
• process.stdin
  标准输入流
• process.nextTick
  比setTimeout效率更高

function doSomething(args,callback){
  (function first(){
    console.log(args)
  })();
  callback();
}
doSomething('args',function call(){
  (function computed(){
    console.log("callback")
  })();
});
console.log("结束")
//args  callback  结束

function doSlowthing(args,callback){
  (function first(){
    console.log(args)
  })();
  process.nextTick(callback);
}
doSlowthing('args',function call(){
  (function computed(){
    console.log("callback")
  })();
});
console.log("结束")
//args  结束  callback

util

• inherits
  继承，只继承prototype原型上的方法和属性
• inspect

function Animal(){
  this.name = 'pig';
  this.toString = function(){
    return this.name
  }
}
var obj = new Animal()
console.log(util.inspect(obj,true))

Animal {
  name: 'pig',
  toString:
   { [Function]
     [length]: 0,
     [name]: '',
     [arguments]: null,
     [caller]: null,
     [prototype]: { [constructor]: [Circular] } } }