Ruby

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. Ruby

require 'chilkat'

success = false

json = Chilkat::CkJsonObject.new()

# First build simple JSON..
json.UpdateInt("test.abc",100)

json.put_EmitCompact(false)
print json.emit() + "\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.to_s() + "\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 true = success and false = 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.to_s() + " (not a valid indicator)" + "\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.to_s() + "\n";
    if (wasFound == true)
        print "The value was present and is 0." + "\n";
    else
        print "no member is present at test.notHere" + "\n";
    end

else
    print "val = " + val.to_s() + "\n";
end

# Alternatively, you could check to see if the member exists beforehand..
if (json.HasMember(path) == true)
    print "val = " + json.IntOf(path).to_s() + "\n";
else
    print "no member at " + path + "\n";
end