您应该使用 filter 方法，该方法接受 callback 函数。

The filter() method creates a new array with all elements that pass the test implemented by the provided function.

此外，使用 typeof 运算符 来找出数组中项目的类型。 typeof 运算符返回一个字符串，指示未评估操作数的类型。

let total = ["10%", "1000", "5%", "2000"];
let percentage = total.filter(function(item){
  return typeof item == 'string' && item.includes('%');
});
console.log(percentage);
let absolute = total.filter(function(item){
  return typeof item == 'number' || !isNaN(item);
});
console.log(absolute);

Make two arrays from one array by separating number and string using advance  
js.

let total = ["10%", 1000, "5%", 2000];
var percentage = total.filter(e => isNaN(e));
var absolute = total.filter(e => !isNaN(e));
console.log({percentage , absolute});