#include<stdio.h>/*
(1)init part - to give a init or a common part which is necessary for prog-
-ram and can't be given commentary lines added on it.
(2)indepent part - only one part can be existed in all demo when executing
a program, Meanwhile,Any other "independent part" shoud be given commentary
lines on it.
*/intmain(){/*
在输入输出函数中:
格式说明由%开始,并以格式字符结束,用于指定各输出值参数的输出格式.
函数printf()中的格式修饰符:
在函数printf()的格式说明中,可以在%和格式符之间插入格式修饰符,用于对输出格式进
行微调,如指定输出数据的域宽,显示精度,左对齐,右对齐等.
*//*
--independent block1
使用const常量定义pi,编程从键盘输入圆的半径radius,计算并输出圆的周长和面积
使其输出的数据保留两位小数点.
*/constdouble pi =3.14159;double radius, circumference, area;printf("Input radius:");scanf_s("%lf",&radius);
circumference =2* pi * radius;
area = pi * radius * radius;printf("printf WITHOUT width or precision specifications:\n");printf("circumference = %f, area = %f\n", circumference, area);printf("printf WITH width or precision specifications:\n");printf("circumference = %7.2f, area = %7.2f", circumference, area);/*
Input radius:5.3
printf WITHOUT width or precision specifications:
circumference = 33.300854, area = 88.247263
printf WITH width or precision specifications:
circumference = 33.30, area = 88.25
*//*
CONCLUSION:
%m.n + 格式字符
m 代表域宽 ---输出数据占m个字符宽度
.n 代表输出精度 ---输出数据显示精度为n,指保留n位小数
注:小数点也占1个字符位置
m为正整数,当输出数据宽度小于m时,数据向右对齐,左边多余位补空格
m为负整数,向左对齐,右边多余位补空格
*//*
precise [prɪˈsaɪs]
① (ADJ-GRADED) 明确的；确切的
You use precise to emphasize that you are referring to an exact thing,
rather than something vague.
② (ADJ-GRADED) 精确的；准确的
Something that is precise is exact and accurate in all its details.
precision [prɪˈsɪʒn]
① (N-UNCOUNT) 精确；精密
If you do something with precision, you do it exactly as it should be done.
specific [spəˈsɪfɪk]
① (ADJ-GRADED) (部位、问题、题目等)特定的，特别的
You use specific to refer to a particular fixed area, problem, or subject.
② (ADJ-GRADED) （表达）明确的，确切的，具体的
If someone is specific, they give a description that is precise and exact.
You can also use specific to describe their description.
specification [ˌspesɪfɪˈkeɪʃn]
① (N-COUNT) 规格;具体要求
A specification is a requirement which is clearly stated,
for example about the necessary features in the design of something.
*//*
函数scanf():
scanf()函数的格式控制字符串中存在除格式说明符以外的其他字符,那么这些字符必须
在输入数据时由用户从键盘原样输入.
scanf()输入数值型数据时, 遇到以下几种情况都认为输入数据结束:
(1)遇到空格符、回车符、制表符;
(2)达到输入域宽;
(3)遇非法字符输入;
*//*
the init part only for block2 to block4
*/int a, b;/*
--independent block2
%2d%2d --GETTING THE RESULT FROM THE FOLLOWING CONCLUSION 1:
*/scanf_s("%2d%2d",&a,&b);printf("a = %d, b = %d\n", a, b);/*
1234
a = 12, b = 34
CONCLUSION 1:
scanf()函数中:
%m + 格式字符:
按照指定宽度从输入的数据中截取所需的m个数据读入到相应变量.
注:scanf() 没有精度修饰符.
*//*
--independent block3
%d%*c%d --GETTING THE RESULT FROM THE FOLLOWING CONCLUSION 2
*///用户可以用"任意字符"作为分隔符进行数据的输入scanf_s("%d%*c%d",&a,&b);//%*c 读取数据进入变量时,忽略读取一个字符型数据printf("a = %d, b = %d\n", a, b);/*
--independent block4
%2d%*2d%2d --GETTING THE RESULT FROM THE FOLLOWING CONCLUSION 2
*///用户输入123456scanf_s("%2d%*2d%2d",&a,&b);printf("a = %d, b = %d\n", a, b);/*
123456
a = 12, b = 56
%*2d --- 代表中间有二位输入的数值型数据被截取忽略读取,之后输入的数据开始读入到相应的变量
CONCLUSION 2:
scanf()函数中:
%*m + 格式字符:
按照指定宽度从输入的数据中截取m个数据忽略掉,后面的数据读入到相应的变量.
*/return0;}
