var arr=[1,2,3,4,5,6,7,8,9,10]; 

    function splitArray(arr,size){

        var result = [];
        var tempArray;

        for(var i = 0; i < arr.length; i++){  
            if(i%size == 0 ){
                if(tempArray){
                    result.push(tempArray);
                }
                tempArray = [];           
            }
     
            tempArray[tempArray.length]=arr[i];
            if(i+1 == arr.length){
                result.push(tempArray);
            }

        }

        return result;
        
    }
    console.log(splitArray(arr,3));   //[[1,2,3],[4,5,6],[7,8,9],[10]]

var arr=[1,2,3,4,5,6,7,8,9,10,11,12,1,2,3,7,8,9]; 

    function splitArray(arr,size){

        var result = [];
        var tempArray;

        for(var i = 0; i < arr.length; i++){  
            if(i%size == 0 ){
                if(tempArray){
                    result.push(tempArray);
                }
                tempArray = [];           
            }
     
            tempArray[tempArray.length]=arr[i];
            if(i+1 == arr.length){
                result.push(tempArray);
            }

        }

        return result;

    }

    Array.prototype.unique = function(){

        var json = {},result=[]; 

            for(var i = 0; i < this.length; i++){
                if (!json[this[i]]){
                    json[this[i]] = 1; 
                    result.push(this[i]); 
                }
            }

        return result;

    }

    console.log(splitArray(arr,3));   //[[1,2,3],[4,5,6],[7,8,9],[10,11,12],[1,2,3],[7,8,9]]
    console.log(splitArray(arr,3).unique());   //[[1,2,3],[4,5,6],[7,8,9],[10,11,12]]

　　var arr=[1,2,3,4,5,6,7,8,9,10,11,12,1,2,3,7,8,9]; 
    function splitArray(arr){

            var json = {};
            var arr1 = [];

            for(var i=0;i<arr.length;i++){
                if( i%3==0 ){
                    json.x = arr[i];
                }else if( i%3==1 ){
                    json.y = arr[i];
                }else if( i%3==2 ){
                    json.z = arr[i];
                    arr1.push(json);
                    json={};
                }
            }

            return arr1;

   }
   console.log(splitArray(arr));   //[{x:1,y:2,z:3},{x:4,y:5,z:6},{x:7,y:8,z:9},{x:10,y:11,z:12},{x:1,y:2,z:3},{x:7,y:8,z:9}]

var arr=[1,2,3,4,5,6,7,8,9,10,11,12,1,2,3,7,8,9]; 
    function splitArray(arr){

            var json = {};
            var arr1 = [];

            for(var i=0;i<arr.length;i++){
                if( i%3==0 ){
                    json.x = arr[i];
                }else if( i%3==1 ){
                    json.y = arr[i];
                }else if( i%3==2 ){
                    json.z = arr[i];
                    arr1.push(json);
                    json={};
                }
            }

            return arr1;

     }

    Array.prototype.unique = function(){
        var json = {},arr1=[];

        for(var i = 0; i < this.length; i++) {
            if (!json[JSON.stringify(this[i])]) {
                json[JSON.stringify(this[i])] = 1; 
                arr1.push(this[i]); 
            }
        }

        return arr1;

    }
    console.log(splitArray(arr));   //[{x:1,y:2,z:3},{x:4,y:5,z:6},{x:7,y:8,z:9},{x:10,y:11,z:12},{x:1,y:2,z:3},{x:7,y:8,z:9}]
    console.log(splitArray(arr).unique());   //[{x:1,y:2,z:3},{x:4,y:5,z:6},{x:7,y:8,z:9},{x:10,y:11,z:12}]