[javascript]多个数组取交集的函数

基本思路：

1.获取长度最短的数组

2.分别针对每组数组构建json（hash）

3.遍历最短的数组，并且匹配其他数组中的数据

function getArrayShare(arr){
var length;
var subArr,subLength;
var mixArr,mixLength;
var i,j,index;
var arrObj = [],obj = {};
var spe = ",";
var key,str=spe;
var _arr=[];

length = arr.length;
mixArr = arr[0]; 
mixLength = mixArr.length;

if(!length)return;

if(length == 1) return mixArr;

for(i=0;i<length;i++){ 
subLength = arr[i].length;
if(mixLength>subLength){
mixLength = subLength;
mixArr = arr[i];
index = i;
}

};

arr.splice(index,1);
length = arr.length;

for(i=0;i<length;i++){
obj = {};
subArr = arr[i];
subLength = subArr.length;
for(j=0;j<subLength;j++){
obj[subArr[j]] = true;
} 
arrObj.push(obj);
}

for(i=0;i<mixLength;i++){
key = mixArr[i];
for(j=0;j<length;j++){
if(arrObj[j][key]&&str.indexOf(spe+key+spe)==-1){
_arr.push(key);
str += key + spe;
}
}; 
};

return _arr;
}

var testArray = [[1,2,3,10],[10,5,1,10,3],[10,3,1]]
console.log(getArrayShare(testArray));

function getArrayShare(arr){

var length;

var subArr,subLength;

var mixArr,mixLength;

var i,j,index;

var arrObj = [],obj = {};

var spe = ",";

var key,str=spe;

var _arr=[];

length = arr.length;

mixArr = arr[0];

mixLength = mixArr.length;

if(!length)return;

if(length == 1) return mixArr;

for(i=0;i<length;i++){

subLength = arr[i].length;

if(mixLength>subLength){

mixLength = subLength;

mixArr = arr[i];

index = i;

}

};

arr.splice(index,1);

length = arr.length;

for(i=0;i<length;i++){

obj = {};

subArr = arr[i];

subLength = subArr.length;

for(j=0;j<subLength;j++){

obj[subArr[j]] = true;

}

arrObj.push(obj);

}

for(i=0;i<mixLength;i++){

key = mixArr[i];

for(j=0;j<length;j++){

if(arrObj[j][key]&&str.indexOf(spe+key+spe)==-1){

_arr.push(key);

str += key + spe;

}

};

return _arr;

}

var testArray = [[1,2,3,10],[10,5,1,10,3],[10,3,1]]

console.log(getArrayShare(testArray));

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