JavaScript JSON Cookbook

The json_encode function takes an optional second argument, which lets you specify arguments to the encoder. The arguments are flags, so you combine them with the binary or | operator. You can pass a combination of the following flags:
JSON_FORCE_OBJECT: This flag forces the encoder to encode the JSON as an object.
JSON_NUMERIC_CHECK: This flag checks the contents of each string in the incoming structure and if it contains a number, converts the string to a number before encoding it.
JSON_PRETTY_PRINT: This flag formats the JSON for easier reading by humans (don't do this in production, as it makes the JSON bigger)
JSON_UNESCAPED_SLASHES: This flag instructs the encoder to not escape slash characters.