C语言入门课程学习笔记2

第8课 - 四则运算与关系运算
第9课 - 逻辑运算与位运算
第10课 - 深度剖析位运算
第11课 - 程序中的选择结构

本文学习自狄泰软件学院唐佐林老师的 C语言入门课程，图片全部来源于课程PPT，仅用于个人学习记录

第8课 - 四则运算与关系运算

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#include <stdio.h>int main()
{int a = 5;int b = 2;double c = 3;c = a / b;printf("c = %f\n", c);c = a % b;printf("c = %f\n", c);return 0;
}/*output:
c = 2.000000
c = 1.000000*/

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#include <stdio.h>int main()
{int a = 1;int b = 2;int c = 3;c = a != b;//1c = a - b >= a + b;//-1>=3    0printf("c = %d\n", c);c = (a < b) + (c < b);//1<2   0<2    2printf("c = %d\n", c);return 0;
}/*output:
c = 0
c = 2*/

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#include <stdio.h>int main()
{int a = 1;int b = 2;int c = 0;c = a != b+a*b;//1!=3  1printf("c = %d\n", c);c = a == b < c== b;//0<0   0printf("c = %d\n", c);return 0;
}/*output:
c = 1
c = 0*/

第9课 - 逻辑运算与位运算

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#include <stdio.h>int main()
{int a = 1;int b = 2;int c = 0;c = a && b;   1&&2   1printf("c = %d\n", c);c = !(a - b) || (c < b);   !(-1)||(0<2)     0||1    1printf("c = %d\n", c);c = 10000;c = !!c;printf("c = %d\n", c);   !0    1return 0;
}/*output:
c = 1
c = 1
c = 1*/

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#include <stdio.h>int main()
{printf("c = %d\n", 5 | 2);      //101|10     111    7printf("c = %d\n", 7 ^ 8);      //111^1000    1111   15printf("c = %d\n", 2 ^ 3);       //10^11      01     1printf("c = %d\n", (15 >> 2) & 13);  //11&1101        1printf("c = %d\n", 173 ^ 60);     //1010 1101^0011 1100     1001  0001    145return 0;
}/*output:
c = 7
c = 15
c = 1
c = 1
c = 145*/

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第10课 - 深度剖析位运算

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#include <stdio.h>int main()
{short a = 1;short b = 2;int c = a - b;//-1    1111 1111 1111  1111 1111 1111 1111  1111c = c >> 4;//  -1printf("c = %d\n", c);c = c * -1 * 16 >> 4; //... ...  0001 0000     1printf("c = %d\n", c);printf("c = %d\n", 16 << 2);  //64return 0;
}/*output:
c = -1
c = 1
c = 64*/

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#include <stdio.h>int main()
{char c = 'A';short a = c;int b = c;printf("c = %c\n", c);//Aprintf("c = %d\n", c);//65printf("a = %d\n", a);//65printf("b = %d\n", b);//65c = 0x40;printf("c = %x\n", c);//40printf("c = %d\n", c);//64c = c << 1;printf("c = %d\n", c);//1000 0000    -128c = c << 1;printf("c = %d\n", c);//   0000 0000    0return 0;
}/*output:
c = A
c = 65
a = 65
b = 65
c = 40
c = 64
c = -128
c = 0*/

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补充点：原码、反码及补码，十进制、二进制、十六进制之间的转换

第11课 - 程序中的选择结构

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#include <stdio.h>int main()
{short a = 1;short b = 2;int c = a - b;if( c > 0 ){printf("a > b\n");}else{printf("a <= b\n");}return 0;
}/*output:
a <= b*/

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#include <stdio.h>int main()
{short a = 2;short b = 2;int c = a - b;if( c > 0 )printf("a > b\n");else if( c == 0 )printf("a == b\n");elseprintf("a < b\n");return 0;
}/*output:
a == b*/