How to convert a string/ char array to a double or float? None of the standard libs seem to want to work

Thank you for the help! to resolve the issue on the Nucleo-F429ZI the following code needs to be added to a JSON file under the main folder called mbed_app.json

{
“target_overrides”: {
“NUCLEO_F429ZI”: {
“target.printf_lib”: “std”
}
}
}

this adds floating point printing functionality to the print lib as this is removed by default