How to run two lines of code at once?

Hello there,
I am programming three ultrasonic sensors to detect distance and light an led if it detects a distance between 1-30 cm. Is there a way that I can make the arduino run all the code for all three of these sensors at once? If so, how?

Any help will be greatly appreciated,
Aditya

Define “at once”

Ultrasonic sensors have to be used sequentially, or they will interfere with each other.

Is there a way that I can make the arduino run all the code for all three of these sensors at once?

No. But the Arduino can read each sensor in order, in a very small amount of time. Use the NewPing library, NOT pulseIn(), to read the ping sensors.