Question

控制台上显示的错误是：

TypeError: Cannot read property '0' of null
    at app.post (/root/src/master.js:24:29)

master.js 24:29就是这个

let outputs = req.body.outputs
  let outs = []
  for (let out of outputs) {
   outs.push({
     address: out.addresses[0],
      value: out.value
    })}
  }

第24行是地址： out.addresses[0],

来自这个json的请求

"outputs": [
{
"value": 10000,
"script": "a91402f42dce015def2fab0b1d6f7f6c742bae66e75e87",
"addresses": [
"31xdnmzVzmAQ5CaWxtiDr3jwCFfeUpHEb1"
],
"script_type": "pay-to-script-hash"
},
{
"value": 1020,
"script": "0014396ef6487043092385338ccfe9d327fb031975d6",
"addresses": null,
"script_type": "pay-to-witness-pubkey-hash"
}
]

有人可以帮我解决这个问题吗？非常感谢！

Answer 1

地址为null。您可以添加空检查

let outputs = req.body.outputs
let outs = []
for (let out of outputs) {
    outs.push({
      address: out.addresses ? out.addresses[0] : '',
      value: out.value
    })}
}

Answer 2

由于您的addresses可以为null（根据您共享的示例输出），

for (let out of outputs) {
   outs.push({
     address: out.addresses ? out.addresses[0] : [], //notice the change here
      value: out.value
    })}
}

如果out.addresses为null，请

设置空数组。

Answer 3

address在对象中的一个位置为空，

因此，您可以使用address运算符添加条件以检查present terniary是否为let outputs = req.body.outputs let outs = [] for (let out of outputs) { outs.push({ address: out.addresses ? out.addresses[0] : '', value: out.value })} }。

address: out.addresses ? out.addresses[0] : '',

<强> The above line checks if

my_variable = "beginning of the string" \ "end of the string" out.addresses`存在，如果是，它将返回else返回空字符串。

TypeError：推送代码后无法读取null的属性“0”

3 个答案: