pxt-calliope/docs/reference/control/assert.md

assert

Stop the program if the assertion condition is false.

control.assert(false)

You can insist that your program will stop at an assert block if a certain condition you check is false. The error number in the assert is written to the serial port with a failure message.

Parameters

• cond: a boolean where true means everything is ok or false which means, stop the program!
• msg: an optional string with a message describing the failed assertion.

Example

Stop the program if a sensor connected to pin P0 sends a low (0) signal.

basic.forever(() => {
    control.assert(pins.digitalReadPin(DigitalPin.P0) == 1)
    basic.pause(1000)
})

See also

panic