Perl

Check if Integer Exists at JSON Path

Demonstrates how to get an integer value at a JSON path, and how to check to see if it exists. Perl

use chilkat();

$success = 0;

$json = chilkat::CkJsonObject->new();

# First build simple JSON..
$json->UpdateInt("test.abc",100);

$json->put_EmitCompact(0);
print $json->emit() . "\r\n";

# This is our JSON:
# {
#   "test": {
#     "abc": 100,
#   }
# }

$path = "test.notHere";

# The call to IntOf will return 0, because it's not present.
# But how do we know if it really was present, and the value was truly 0?
$val = $json->IntOf($path);
print "val = " . $val . "\r\n";

# We cannot use LastMethodSuccess because LastMethodSuccess only applies
# to methods that:
# - return a string
# - return a new Chilkat object, binary bytes, or a date/time.
# - returns a boolean status where 1 = success and 0 = failed.
# - returns an integer where failure is defined by a return value less than zero.
# The IntOf method fits none of these requirements, and therefore the LastMethodSuccess 
# is not a valid indicator..
$wasFound = $json->get_LastMethodSuccess();
print "wasFound = " . $wasFound . " (not a valid indicator)" . "\r\n";

# Instead, if the returned value is 0, we can double-check to see if the member was truly there..
if ($val == 0) {
    $wasFound = $json->HasMember($path);
    print "wasFound = " . $wasFound . "\r\n";
    if ($wasFound == 1) {
        print "The value was present and is 0." . "\r\n";
    }
    else {
        print "no member is present at test.notHere" . "\r\n";
    }

}
else {
    print "val = " . $val . "\r\n";
}

# Alternatively, you could check to see if the member exists beforehand..
if ($json->HasMember($path) == 1) {
    print "val = " . $json->IntOf($path) . "\r\n";
}
else {
    print "no member at " . $path . "\r\n";
}