Dolphins have excellent eyesight and hearing. Underwater they use echolocation. Echolocation is kind of like sonar where dolphins make a sound and then listen to the echo. Their hearing is so sensitive to these echoes that they can almost see objects in the water by hearing. This allows dolphins to locate food in cloudy or dark water.
This is the latest accepted revision, reviewed on 16 April 2017. Source code of a simple computer program written in the C programming language, which will output the Hello, world! message when compiled and run. A programming language is a formal computer language designed to communicate instructions to a machine, particularly a computer.
Variables and types. The usefulness of the Hello World programs shown in the previous chapter is rather questionable. We had to write several lines of code, compile them, and then execute the resulting program, just to obtain the result of a simple sentence written on the screen.