js问题不会做了 求助

Question

var arr = ["a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"];

var sarr = [4,10,18];

想得到5-9  11-17  19-最后

想得到result 数组 

var result = ["fghij","lmnopqr","tuvwxyz"];

sarr可能的值
sarr = [20] 得到21-最后 var result = ["vwxyz"];

sarr = [20,24] 得到21-23 25-最后 var result = ["vwx","z"];

求助js该怎么写

Answer 1

&nbsp; &nbsp; &nbsp; &nbsp; var arr = ["a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"]&nbsp; &nbsp; &nbsp; &nbsp; var sarr = [4,10,18], result = []&nbsp; &nbsp; &nbsp; &nbsp; for(var i = 0, l = sarr.length; i<l ; i++){&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; sarr[i+1] = sarr[i+1] ? sarr[i+1] : arr.length&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; result[i] = arr.slice(sarr[i]+1,sarr[i+1]).join('')&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; console.log(result)