如何从“key:value”格式的键访问 json 值？

Question

This is my payload object received in my backend running node.js.I want to access username testdoctor using key cognito:username .However key is again in form of key:value format.How do i access it?

payload.email gives the email value but payload.' cogito:username ' doesn't do the trick.

{
  'cognito:username': 'testdoctor',
  exp: 1621155498,
  iat: 1621151899,
  email: 'aayushbakliwal.2625@gmail.com'
}

Answer 1

When a property names contains restricted characters that are not allowed in a Javascript identifier (the colon in this case), then you have to use the bracket syntax for accessing the property name:

payload['cognito:username']

Obviously, it is easier to program if you you don't have code that uses these restricted characters in property names, but if you're stuck with it, then you can use the bracket syntax as shown above. The same would be true if the property name contained a space too.