If

Conditionally run code depending on whether a Boolean condition is true or false.

if(true) {
}

Click on the dark blue gear icon (see above) to add an else or if to the current block.

Example: adjusting screen brightness

If the light level is < 100, this code sets the brightness to 255 when the button A is pressed:

input.onButtonPressed(Button.A, () => {
    if(input.lightLevel()<100){
        led.setBrightness(255);
    }
})