The Art of Agile Development

Pair Programming

Note

Programmers, Whole Team

We help each other succeed.

Do you want somebody to watch over your shoulder all day? Do you want to waste half your time sitting in sullen silence watching somebody else code?

Of course not. Nobody does—especially not people who pair program.

Pair programming is one of the first things people notice about XP. Two people working at the same keyboard? It’s weird. It’s also extremely powerful and, once you get used to it, tons of fun. Most programmers I know who tried pairing for a month find that they prefer it to programming alone.

Why Pair?

This chapter is called Thinking, yet I included pair programming as the first practice. That’s because pair programming is all about increasing your brainpower.

When you pair, one person codes—the driver. The other person is the navigator, whose job is to think. As navigator, sometimes you think about what the driver is typing. (Don’t rush to point out missing semicolons, though. That’s annoying.) Sometimes you think about what tasks to work on next and sometimes you think about how your work best fits into the overall design.

This arrangement leaves the driver free to work on the tactical challenges of creating rigorous, syntactically correct code without worrying about the big picture, and it gives the navigator the opportunity to consider strategic issues without being distracted by the details of coding. Together, the driver and navigator create higher-quality work more quickly than either could produce ...