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The question it more about the design of the code and how it could be written better. The code itself works as it should.

A little about the code itself: the function checks the object passed as the first argument and either return a string with the type of object (array, date, xmlhttprequest, etc.) or a Boolean when comparing an object with a string value.

The function can also iterate through an array of objects and returns a Boolean value, an array of Boolean results, or an object.

(function ( global ) {
  "use strict";
  Object.type = function type( testObject, testAgainst, returnType ) {
    var result, getType = function ( object ) {
      var result;
      if ( object && object.nodeType !== undefined ) {
        result = 'dom';
      }
      else if ( object === global ) {
        result = 'global';
      }
      else {
        result = ({}).toString.call( object ).match( /\s([a-zA-Z]+)/ )[1].toLowerCase();
      }
      return result;
    };

    if ( getType( testAgainst ) !== 'undefined' ) {
      if ( getType( testAgainst ) === 'string' ) {
        return getType( testObject ) === testAgainst;
      }
      else if ( getType( testAgainst ) === 'array' ) {
        if ( getType( returnType ) === 'undefined' ) {
          returnType = 'boolean';
        }
        result = {
          'boolean': function () {
            return testObject.every(function ( member, index ) {
              return getType( member ) === testAgainst[index];
            });
          },
          'array': function () {
            return testObject.map(function ( member, index ) {
              return getType( member ) === testAgainst[index];
            });
          },
          'object': function () {
            var result = {};
            testObject.forEach(function ( member, index ) {
              result[ getType( member ) ] = getType( member) === testAgainst[index];
            });
            return result;
          }
        };
        return result[ returnType ]();
      }
    }
    return getType( testObject );
  };
}( this ));

Usage examples:

  (function () {
    var objects = [null, 0, undefined, new Date(), new XMLHttpRequest(), function () {}, {}, [], 'string'],
      matches = ['null', 'number', 'undefined', 'date', 'xmlhttprequest', 'function', 'object', 'array', 'string'],
      misses = ['array', 'number', 'string', 'date', 'xmlhttprequest', 'function', 'object', 'number', 'string'];

    console.dir({
      "objects array: ": objects,
      "matches array: ": matches,
      "misses array: ": misses,
      "Object.type( {} )": Object.type( {} ), //returns 'object'
      "Object.type( 2013, 'number' )": Object.type( 2013, 'number' ), //returns true
      "Object.type( objects, matches )": Object.type( objects, matches), //returns true
      "Object.type( objects, misses )": Object.type( objects, misses ), //returns false
      "Object.type( objects, matches, 'object' )": Object.type( objects, matches, 'object' ),
      "Object.type( objects, matches, 'array' )": Object.type( objects, matches, 'array' ), //returns Array[9] (true, true, true, true, true, true, true, true, true)
      "Object.type( objects, misses, 'object' )": Object.type( objects, misses, 'object' ),
      "Object.type( objects, misses, 'array' )": Object.type( objects, misses, 'array' ) //returns Array[9] (false, true, false, true, true, true, true, false, true)
    });
  }());

The problem with the design that mainly bugs me is that the majority of the code is inside nested if statements.

What design changes I could make to this code to make it ready for production?

Edit:
I've created a gist where I updated the above code based on comments (https://gist.github.com/silverstrike/5108601)

4

1 回答 1

0

您应该使用提前返回（没有充分的理由不使用它们），它将大大简化您的代码并取消嵌套所有这些 if 语句。例如，getType变成这样：

function getType(object) {
    if (object && object.nodeType !== undefined)
        return 'dom';
    if (object === global)
        return 'global';
    return ({}).toString.call(object).match(/\s([a-zA-Z]+)/)[1].toLowerCase();
}

您已经在使用另一种替代一百万个 IF 语句（对象文字），但您可能只选择其中一个而不是混合它们。特别是在你的情况下，你有一个要执行的函数对象，一些 if 语句会更短/更容易读/写。

于 2013-03-07T13:34:31.683 回答