二维数组去重

示例

var arr = [["aa","bb","cc"],["aa","bb","cc"],["b","b","v"]];  
var hash = {};  
var result = [];  
for(var i = 0, len = arr.length; i < len; i++){  
    if(!hash[arr[i]]){  
        result.push(arr[i]);  
        hash[arr[i]] = true;  
    }  
}  
console.log(result);  

思路

1. 使用对象的key唯一性来实现二维数组的去重
2. 将一维数组元素作为key，传递给对象