Javascript how to check if incoming param is an object

Question

How to check if an incoming param to my function is an proper object in javascript?

code

function abc(object1, data1) {
    if(i need to verify here object1 is a proper JSON then only it should proceed) {
        //do the operation
    }
}

Does this answer your question? [Check if a value is an object in JavaScript](https://stackoverflow.com/questions/8511281/check-if-a-value-is-an-object-in-javascript) — Lemondoge, Dec 06 '20 at 18:08
Again, JSON string and JavaScript object is different thing. Please be more specific so we can help you. — Ballon Ura, Dec 06 '20 at 18:13
Then https://stackoverflow.com/questions/3710204/how-to-check-if-a-string-is-a-valid-json-string-in-javascript-without-using-try should answer your question. (note: the question was about doing it without using `try/catch`) — Lemondoge, Dec 06 '20 at 18:13
sorry that dosen't help i need to put a check in if condition if the incoming parameter is JSON — Tarun, Dec 06 '20 at 18:17
What are you passing? You call it object1 but is it `'{"a":"b","c":"d"}'` or `{"a":"b","c":"d"}` — mplungjan, Dec 06 '20 at 18:48

score 2 · Answer 1 · answered Dec 06 '20 at 18:33

2

The function below can be used to check if provided data is a valid JSON, for an object (string, boolean, ...) it will return false:

const isJson = (data) => {
   try {
      return Boolean(JSON.parse(data));
   } catch {
      return false
   }
}

answered Dec 06 '20 at 18:33

Oleksandr Sakun

452
4
9

score 0 · Answer 2 · answered Dec 06 '20 at 19:18

function abc(object1, data1) {
    let isJson;
    try {
        JSON.parse(object1);
        isJson = true;
    } catch (ignore) {}
    if (isJson) {
        //do the operation
        console.log("object1 - " + object1 + " - is json-parseable");
        return;
    }
    console.log("object1 - " + object1 + " - is not json-parseable");
}

// test
abc("null");            // object1 - null - is json-parseable
abc("{\"aa\":\"bb\"}"); // object1 - {"aa":"bb"} - is json-parseable
abc(undefined);         // object1 - undefined - is not json-parseable
abc("syntax error");    // object1 - syntax error - is not json-parseable

Javascript how to check if incoming param is an object

2 Answers2