The HTTP client helper functions are used for error handling.

httpGetLastErrorCode

This function gets the last error code set.

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Parameter	Description
Returns	The HTTP status code. It will be `-1` if no error occurred. Note that calling the `httpGetLastErrorCode()` function should only be done when the previous POST/GET request returned null.

httpGetLastErrorMessage

This function gets the last error message.

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Parameter	Description
Returns	The HTTP status message. It will be `null` if no error occurred. Note that calling the `httpGetLastErrorMessage()` function should only be done when the previous POST/GET request returned null.

This function gets the last response if the connection failed but the server sent useful data nonetheless.

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Parameter	Description
Returns	A document from the HTTP server. It will be an empty string if no error occurred. Note that calling the `httpGetLastErrorResponse()` function should only be done when the previous POST/GET request returned null.

This function retrieves the header from the last HTTP response.

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