JsonVariant::measureLength()
This page covers ArduinoJson 5.13.5, consider upgrading to version 6.16.1.
This page covers ArduinoJson 5.13.5, consider upgrading to version 6.16.1.
Description
Computes the length of the minified JSON document that JsonVariant::printTo() produces, excluding the null-terminator.
This function is handy to fill the Content-Length header.
Signature
size_t measureLength() const
Return value
The number of characters that JsonVariant::printTo() produces, excluding the null-terminator.
Example
// Send headers
client.println("Content-Type: application/json");
client.print("Content-Length: ");
client.println(root.measureLength());
// Terminate headers
client.println();
// Send body
root.printTo(client);