官术网_书友最值得收藏!

The calculator

The first calculator was invented in 1966 at Texas Instruments (http://www.ti.com/corp/docs/company/history/timeline/eps/1960/docs/67-handheld_calc_invented.htm) and was able to do addition, subtraction, multiplication, and pision. The calculator had eighteen keys and could display twelve numbers on the screen. While it doesn't seem like much at first, especially compared to the technology we now enjoy, there is quite a lot of code and decision making that go into the operations that a basic calculator performs.

When we want to figure out how something works, we need to break it down into smaller parts. Let's take a look at how the calculator adds numbers together:

  1. First, the calculator needs power.
  2. The user enters the first number.
  3. The user presses an operation key (+, -, *, or /).
  4. The user enters a second number.
  5. The user presses the = key.
  6. Then, an answer is printed to the screen.

On a basic calculator, the computer does not keep all of the numbers on the screen. The computer must store the first number that the user entered in its memory.

We will run our first calculator program inside of the terminal/command prompt, so there are other things we must consider in addition to how the numbers will be stored. For example:

  • How will we prompt the user to get the information that we need?
  • What happens if the user enters a text string instead of integers or floats?
  • What happens if the user enters numbers as a string instead of as integers or floats?

These are just some of the logical questions that need to be considered as we plan how to write our own calculator program. Can you think of any other problems that need to be solved?

主站蜘蛛池模板: 华亭县| 大宁县| 灵丘县| 永城市| 红原县| 星子县| 泗阳县| 泸西县| 莒南县| 互助| 威海市| 蛟河市| 海淀区| 璧山县| 喀喇| 绿春县| 牙克石市| 荔波县| 惠东县| 阿拉尔市| 昌平区| 淮南市| 洛南县| 阿尔山市| 永康市| 德江县| 吉木乃县| 朝阳区| 竹北市| 海晏县| 定边县| 深水埗区| 门源| 安宁市| 稻城县| 巴南区| 江陵县| 仙居县| 维西| 马山县| 温宿县|