~~~ var arr = [1,2,3,4,5,6]; var pages=[]; arr.forEach((item,index)=>{ const page = Math.floor(index/3); if(!pages[page]){ pages[page]=[]; } pages[page].push(item); }) console.log(pages); ~~~ ~~~ var arr = [1,2,3,4,5,6,7,8,9]; var result = []; //數組被切的起始位置 for(var i=0;i<arr.length;i+=3){ var add = arr.slice(i,i+3); console.log(add); result.push(add); } console.log(result); //判斷條件,數組能被切幾次 var newarr=[]; for(let i=0;i<arr.length/3;i++){ newarr[i]=arr.slice(3*i,3*(i+1)); } console.log(newarr) ~~~