``` <script> var arr = [1,3,2,5,10,100,50]; var max = arr[0]; for(var i=0;i<arr.length;i++){ if(max<arr[i]){ max=arr[i] } } console.log(max); </script> ``` 封裝后 ``` <script> function getArrayMax(array){ var max = array[0]; for(var i=0;i<array.length;i++){ if(max<array[i]){ max = array[i]; } } return max; } var max = getArrayMax([10,20,30,40,50]); console.log(max); </script> ```