• Borislav Kosharov (12/12) Oct 06 2015 I'm using std.json for parsing json. I need to check if a
• via Digitalmars-d-learn (9/11) Oct 06 2015 try
• Fusxfaranto (14/26) Oct 06 2015 Additionally, just like associative arrays, if you need to access
• Marco Leise (13/26) Oct 06 2015 And you could go further and write
• Borislav Kosharov (1/1) Oct 08 2015 Thanks guys that was I was looking for!

Borislav Kosharov <boby_dsm abv.bg> writes:

I'm using std.json for parsing json. I need to check if a 
specific string key is in JSONValue.object. The first thing I 
tried was:

JSONValue root = parseJSON(text);
if(root["key"].isNull == false) {
     //do stuff with root["key"]
}

But that code doesn't work, because calling root["key"] will 
throw an exception of key not fount if "key" isn't there.

I need some method `root.contains("key")` method to check if the 
object has a key.

Thanks in advance!

via Digitalmars-d-learn <digitalmars-d-learn puremagic.com> writes:

On Tue, Oct 06, 2015 at 08:28:46PM +0000, Borislav Kosharov via
Digitalmars-d-learn wrote:
 JSONValue root = parseJSON(text);
 if(root["key"].isNull == false) {

try

if("key" in root) {
	// it is there
} else {
	// it is not there
}


you can also do

if("key" !in root) {}

Fusxfaranto <fusxfaranto gmail.com> writes:

On Tuesday, 6 October 2015 at 20:44:30 UTC, via 
Digitalmars-d-learn wrote:
 On Tue, Oct 06, 2015 at 08:28:46PM +0000, Borislav Kosharov via 
 Digitalmars-d-learn wrote:
 JSONValue root = parseJSON(text);
 if(root["key"].isNull == false) {

 try

 if("key" in root) {
 	// it is there
 } else {
 	// it is not there
 }


 you can also do

 if("key" !in root) {}

Additionally, just like associative arrays, if you need to access 
the value, you can get a pointer to it with the in operator (and 
if the key doesn't exist, it will return a null pointer).

const(JSONValue)* p = "key" in root;
if (p)
{
     // key exists, do something with p or *p
}
else
{
     // key does not exist
}

Marco Leise <Marco.Leise gmx.de> writes:

Am Tue, 06 Oct 2015 21:39:28 +0000
schrieb Fusxfaranto <fusxfaranto gmail.com>:

 Additionally, just like associative arrays, if you need to access 
 the value, you can get a pointer to it with the in operator (and 
 if the key doesn't exist, it will return a null pointer).
 
 const(JSONValue)* p = "key" in root;
 if (p)
 {
      // key exists, do something with p or *p
 }
 else
 {
      // key does not exist
 }

And you could go further and write

if (auto p = "key" in root)
{
     // key exists, do something with p or *p
}
else
{
     // key does not exist
}

-- 
Marco

Borislav Kosharov <boby_dsm abv.bg> writes:

Thanks guys that was I was looking for!