overflow : hidden;
text-overflow: ellipsis;
display: -webkit-box;
-webkit-line-clamp: 2;
-webkit-box-orient: vertical;
一维数组变成二维数组
let arr = [1,2,3,4,5,6]
let result=[]
for(let i=0;i<arr.length;i+=3){
result.push(arr.slice(i,i+3))//拆成长度为3的二维数组
}//result的结果是[[1,2,3],[4,5,6]]