JsonVariant::measureLength()
This page covers ArduinoJson 5.13.5, consider upgrading to version 6.18.0.
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);