item有值，但在Uint8Array中返回'undefined'(item has value but in Uint8Array return 'undefined')

 嗨，我有这样的Uint8Array 
 
var ar = new Uint8Array();
ar[0] = 'G';
ar[1] = 0x123;
 
 第二个索引是一个十六进制数，我想检查ar[1]是否大于零或不是，所以我写这个代码： 
 
if(ar[1] > 0){
  console.log("OK");
}
else{
  console.log("NOP")
}
 
 但如果我写console.log(ar[1])我得到'undefined'。 这是我创建的一个简单的jsbin 。 

hi i have Uint8Array like this 
 
var ar = new Uint8Array();
ar[0] = 'G';
ar[1] = 0x123;
 
the second index is a hexa decimal number and i want to check ar[1] is grater than zero or not so i write this code : 
 
if(ar[1] > 0){
  console.log("OK");
}
else{
  console.log("NOP")
}
 
but if i write console.log(ar[1]) i get 'undefined'. this is a simple jsbin that i created.

原文：https://stackoverflow.com/questions/45343505