I thought the bulb had gone out on my dining area overhead pendant light. Changed the bulb and it still didn't light up. All the electrical appliances around it work. I checked the circuit breakers and nothing was amiss there. The switch is on a double switch with an outdoor light that is fine. What might be the source of the problem? I use this light every day and it just suddenly stopped working. Thanks!

You really need a voltage tester to check the fixture, the switch, etc...
The answer is likely simple if you have the right tools.
Resist the urge to guess at the answer, learn to use a tester if you
Don't already know.

I'm sure you tried a "known" good bulb. I have seen people install new bad bulbs, and not think the bulb could be bad.
Maybe another bulb, or use a tester as mentioned, and start at the switch.