Thread overview
How to detect whethere if a JSON node exists
Apr 13, 2020
Adnan
Apr 13, 2020
Adam D. Ruppe
Apr 13, 2020
Adnan
April 13, 2020
In the following code, I want to process an json array (returned by the value of "posts") that might or might not have "com" key. If a "com" key does not exist, I want to ignore that item in the json array.

        uint[string] wordTable;

	const auto j = parseJSON(get(link));
	foreach (node; j["posts"].array()) {
		import std.stdio : writeln;
		import std.utf : decode;

		import std.algorithm: splitter;
		foreach(word; getStr(node["com"].str()).splitter(' ')) { // here!
			if (word != "") wordTable.require(word, 0)++;
		}
	}

Now in the above inner loop getStr(node["com"].str()) crashes in runtime if an array does not contain "com" node. I want to avoid that. How should I proceed?
April 13, 2020
On Monday, 13 April 2020 at 02:20:39 UTC, Adnan wrote:
> Now in the above inner loop getStr(node["com"].str()) crashes in runtime if an array does not contain "com" node. I want to avoid that. How should I proceed?

Try:

if("com" in node) {

}
April 13, 2020
On Monday, 13 April 2020 at 02:22:33 UTC, Adam D. Ruppe wrote:
> On Monday, 13 April 2020 at 02:20:39 UTC, Adnan wrote:
>> Now in the above inner loop getStr(node["com"].str()) crashes in runtime if an array does not contain "com" node. I want to avoid that. How should I proceed?
>
> Try:
>
> if("com" in node) {
>
> }

Came back here to say that I found exactly this solution. Thanks.