随题而学（二）多维数组转一维数组

浏览数：21 / 时间：2015年06月08日

多维数组转一维数组：[1,[2,3]] ==》 [1,2,3]

function tran(array){
    if(Object.prototype.toString.call(array) != ‘[object Array]‘){
        alert(Object.prototype.toString.call(array) + "非数组")
        return ;
    }
    
    var newArr = [];
    
    function trans(arr){
        for (var num = 0; num < arr.length;num ++){
            if(arr[num].length){
                trans(arr[num]);
            } else {
                newArr.push(arr[num]);
            }
        }
    }
    
    trans(array);
    return newArr;
}

[javascript]

op = Object.prototype,  
ostring = op.toString,  
...  
function isFunction(it) {  
    return ostring.call(it) === ‘[object Function]‘;  
}  
function isArray(it) {  
    return ostring.call(it) === ‘[object Array]‘;  
}

Object.prototype.toString 与 typeof 区别：

typeof

[plain]

在使用 typeof 运算符时采用引用类型存储值会出现一个问题，无论引用的是什么类型的对象，它都返回 "object"。

ECMA 对Object.prototype.toString的解释

[plain]

Object.prototype.toString ( )
When the toString method is called, the following steps are taken:
If the this value is undefined, return "[object Undefined]".
If the this value is null, return "[object Null]".
Let O be the result of calling ToObject passing the this value as the argument.
Let class be the value of the [[Class]] internal property of O.
Return the String value that is the result of concatenating the three Strings "[object ", class, and "]".

[javascript]

var oP = Object.prototype,  
toString = oP.toString;  
  
console.log(toString.call([123]));//[object Array]  
console.log(toString.call(‘123‘));//[object String]  
console.log(toString.call({a: ‘123‘}));//[object Object]  
console.log(toString.call(/123/));//[object RegExp]  
console.log(toString.call(123));//[object Number]  
console.log(toString.call(undefined));//[object Undefined]  
console.log(toString.call(null));//[object Null]

参考：http://my.oschina.net/sfm/blog/33197，http://blog.csdn.net/spy19881201/article/details/12192767，http://www.cnblogs.com/Aralic/p/4397015.html

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随题而学（二）多维数组转一维数组