Reads a double-precision floating-point value from a JSON object by key.
Takes json string and key string.
Returns double value, or 0.0 if key not found.
JSON
Parameters & Returns
Parameters
jsonString
keyString
Returns
Double
Quick Summary
Reads a double-precision floating-point value from a JSON object by key.
Takes json string and key string.
Returns double value, or 0.0 if key not found.
Technical Exegesis...
Reads a double-precision floating-point value from a JSON object by key. Takes json string and key string. Calls FindKeyPosition helper to search for "\"key\":" pattern. If key not found, returns 0.0. If found, calls atof to parse double from json+pos. Returns double value, or 0.0 if key not found.
This function deserializes floating-point number from JSON string. FindKeyPosition searches for exact key match with quotes. atof parses numeric characters including decimal point and exponent notation.
Reads a double-precision floating-point value from a JSON object by key. Takes json string and key string. Calls FindKeyPosition helper to search for "\"key\":" pattern. If key not found, returns 0.0. If found, calls atof to parse double from json+pos. Returns double value, or 0.0 if key not found.
This function deserializes floating-point number from JSON string. FindKeyPosition searches for exact key match with quotes. atof parses numeric characters including decimal point and exponent notation. Returns 0.0 for missing keys (ambiguous - could be actual zero value). Use for reading decimal properties from JSON documents. Common pattern: pi = jsonReadDouble(json, "pi"), gravity = jsonReadDouble(json, "gravity"). Pair with jsonWriteDouble for round-trip serialization. Handles scientific notation (1.5e10). Precision depends on double type.