解析JSON对象，并将值作为单引号字符串传递

Question

I an getting aws event parameter as follow in the lambda call. let event = { pathParameters: '{"foo":"35314"}' }

When I am trying to validate the parameter in condition , it cant find foo key on pathParameters

Here my condition check

if (event.pathParameters && event.pathParameters.foo) {
   //do something
} else {
   console.log('fail');
}

It going in else condition . I tried JSON.parse(JSON.strinify(event)) . It did not help. I do get the Object if I do JSON.parse(event.pathParameters) . Any way to resolve the issue on root level object.

Answer 1

No, you can't parse the event to get access to the '{"foo": "35314}'" , you need to parse the event.pathParameters value to get the actual foo and its value, 35314

 let event = { pathParameters: '{"foo":"35314"}' } if (event.pathParameters && JSON.parse(event.pathParameters).foo) { console.log("'foo' =", JSON.parse(event.pathParameters).foo); } else { console.log('fail'); } 

Answer 2

这是因为要获取的数据具有pathParameters字符串化的JSON，因此您必须使用该键进行解析，例如

JSON.parse(event.pathParameters).foo

Answer 3

let event = { pathParameters: '{"foo":"35314"}' } // foo is a string

if (event.pathParameters) {
   try {
      const { foo } = JSON.parse(event.pathParameters);
      // use foo
   } catch (jsonError) {
     console.log('There was some json parse error', jsonError);
   } 
} else {
   console.log('fail');
}

You need to parse the data from event.pathParameters

Answer 4

 function doSomething(event) { let pathParametersObj = JSON.parse(event.pathParameters); if (pathParametersObj && pathParametersObj.foo) { //do something console.log('pass'); } else { console.log('fail'); } } let event1 = { pathParameters: '{"foo":"35314"}' } let event2 = { pathParameters: null } doSomething(event1); doSomething(event2);