careful-single-quotes-break-JSON.js

const greetings = JSON.stringify({Hello: 'World!'})
console.log(greetings) // {"Hello":"World!"}
console.log(JSON.parse(greetings)) // Object { Hello: "World!" }

// JSON requires double quotes:
JSON.parse("{\"Hello\":\"World!\"}") // Object { Hello: "World!" }
JSON.parse(`{"Hello":"World"}`) // Object { Hello: "World!" }
try {
  JSON.parse("{'Hello':\"World!\"}") 
} catch(e) { console.log(e) } // SyntaxError: JSON.parse: expected property name or '}' at line 1 column 2 of the JSON data
try {
  JSON.parse("{\"Hello\":'World!'}") 
} catch(e) { console.log(e) } // SyntaxError: JSON.parse: unexpected character at line 1 column 10 of the JSON data