如何声明和访问全局变量 [英] How to declare and access global variable

问题描述

  // File1.js 
 var arr = [] ; 
函数insertName {
 var name =josh; 
 arr.push（name）; 
返回名称; 
}; 
函数validName（key）{
 var index = arr.indexOf（key）; 
 if（index == -1）{
 return false; 
} else {
 return true; 
} 
} 
 
 var result = insertname（）; 
 exports.arr = arr; 
 exports.validName = validName; 
  

  // File2.js 
 var file1 = require（./ File1.js）; 
 var name =josh; 
 var verify = file1.validName（name）; 
 if（verify）{
 cosnole.log（Valid name）; 
} else {
 console.log（Error）; 
} 
 
节点File1.js 
节点File2.js 
  

当Im执行File2.js时，Im开始为arr []定义未定义。有人可以帮助我在下面的代码中执行什么操作

解决方案

b
$ b

File1.js

  var arr = []; 
 
函数insertName（）{
 var name =josh; 
 arr.push（name）; 
返回名称; 
}; 
 
函数validName（key）{
 var index = arr.indexOf（key）; 
 if（index == -1）{
 return false; 
} else {
 return true; 
} 
} 
 
 var result = insertName（）; 
 exports.validName = validName; 
  

File2.js

  var file1 = require（./ File1.js）; 
 var name =josh; 
 var verify = file1.validName（name）; 
 
 if（verify）{
 console.log（Valid name）; 
} else {
 console.log（Error）; 
} 
  

What Im doing wrong in the below code?

//File1.js
var arr = [];
function insertName {
    var name = "josh";
    arr.push(name);
    return name;
};
function validName(key) {
var index = arr.indexOf(key);
    if (index == -1) {
        return false;
    } else {
        return true;
    }
}

var result = insertname();
exports.arr = arr;
exports.validName = validName;

//File2.js
var file1 = require("./File1.js");
var name = "josh";
var verify = file1.validName(name);
if(verify) {
cosnole.log("Valid name");
}else {
console.log("Error");
}

node File1.js
node File2.js

When Im executing File2.js, Im gettin undefined for arr[]. Can someone help me what Im doing in the below code

解决方案

Your code contains mistakes change your code like below

File1.js

  var arr = [];

  function insertName() {
        var name = "josh";
        arr.push(name);
        return name;
  };

  function validName(key) {
      var index = arr.indexOf(key);
      if (index == -1) {
      return false;
    } else {
        return true;
   }
 }

 var result = insertName();
 exports.validName = validName;

File2.js

  var file1 = require("./File1.js");
  var name = "josh";
  var verify = file1.validName(name);

 if(verify) {
    console.log("Valid name");
 } else {
      console.log("Error");
 }

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