C语言 复习提纲.doc

1、 C程序结构#include “reg51.h”声明语句main( ) 只有一个,执行从main开始程序内容 （语句是以 ; 结束）2、数据定义int a，b=0; float x=2.6; char A ;定义时要考虑变量的大小及类型3、运算符与表达式（详见P47表3-2）注意：作用和级别高低关系（排列从高到低）！（非）算术运算符（+ - * / %）关系运算符& | = 4、选择结构语句 if语句： main( )int a,b,c,max,min; printf(input three numbers: ); scanf(%d，%d，%d,&a,&b,&c); if(ab)max=a;min=b; elsemax=b;min=a; if(maxc)min=c; printf(max=%dnmin=%d,max,min);Switch语句：main()float a,b;char c;printf(input expression:a+(-,*,/)b n);scanf(%f%c%f,&a,&c,&b);switch(c) case +: printf(%fn,a+b);break; case-: printf(%fn,a-b);break; case*: printf(%fn,a*b);break; case/: printf(%fn,a/b);break; default: printf(input errorn);5、循环语句Goto语句main()int i,sum=0;i=1;loop:if(i=100) sum=sum+i; i+; goto loop;printf(%dn,sum);While语句main()int i,sum=0;i=1; while(i=100) sum=sum+i; i+; printf(%dn,sum);do-while语句main()int i,sum=0; i=1; do sum=sum+i; i+;while(i=100) printf(%dn,sum);Break语句main()int i=0; char c; while(1) /*设置循环*/ c=0; /*变量赋初值*/ while(c!=13&c!=27) /*键盘接收字符直到按回车或Esc键*/ c=getch(); printf(%cn, c); if(c=27) break; /*判断若按Esc键则退出循环*/ i+; printf(The No. is %dn, i); printf(The end);Continue语句main()char c; while(c!=13) /*不是回车符则循环*/ c=getchar( ); if(c=0X1B) continue; /*若按Esc键不输出便进行下次循环*/ printf(%cn, c);一维数组：#include stdio.hvoid main()int array10,i,max,min; for(i=0;i=0;i-)printf(array%d=%dn,i,arrayi);if(arrayimax)max=arrayi;if(arrayimin)min=arrayi;printf(max=%dn,max);printf(min=%d,min);学习拓展上机作业：在上例基础上完成求平均值的代码#include stdio.hvoid main()int array10,i,max,min,sum=0; float ave;for(i=0;i=0;i-)printf(array%d=%dn,i,arrayi);if(arrayimax)max=arrayi;if(arrayimin)min=arrayi;printf(max=%dn,max);printf(min=%dn,min);ave=sum/10;printf(ave=%.1f,ave);二维数组定义及引用：int a25=0,1,2,3,4,5,6,7,8,9; 或=0,1,2,3,4,5,6,7,8,9;字符数组定义及引用：Char name =“xiaoli”; 或=”xiaoli”; 或=x,i,a,o,l,i;53 62 53 score00 score01 score0258 98 85 score10 score11 score1286 84 75 score20 score21 score22#include stdio.hvoid main()int i, ls=0,ns=0,os=0;char doc30;printf(please input a doc:);for(i=0;i30;i+)scanf(%c,&doci);for(i=0;i30;i+)if(0=doci&doci=9) ns+;else if(A=doci&doci=Z|a=doci&doci=z)ls+;else os+;printf(ls:%d,ns:%d,os:%dn,ls,ns,os);函数定义：（加主函数才能运行）#include stdio.hint hsum()int i=0,sum=0;while(ib)return a;else if(afir_b?fir_a:fir_b;int max_last(int la_a,int la_b,int la_c)return max_first(max_first(la_a,la_b),la_c);main()int a,b,c,max;printf(please input a,b,c:);scanf(%d,%d,%d,&a,&b,&c);max=max_last(a,b,c);printf(max=%d,max);数组为函数参数：#include stdio.hcheck_char(char ch)if(A=ch&ch=Z)|(a=ch&ch=z)printf(%cn,ch); else printf(not a chn);main()char cc10;int i;printf(please input 10 ch:);for(i=0;i10;i+)scanf(%c,&cci);for(i=0;i10;i+)check_char(cci);指针：变量的指针就是变量的地址。存放变量地址的变量是指针变量1) &:取地址运算符。*：指针运算符（或称“间接访问” 运算符）定义；int *p1;引用：main() int a,b; int *pointer1, *pointer2; a=100;b=10; pointer_1=&a;pointer_2=&b; printf(%d,%dn,a,b); printf(%d,%dn,*pointer1, *pointer2);指针与数组：#include stdio.h#define N 20main()char *a;int change_sum=0,loop;char arrayN=fsnaslfnJFBJGNK4515304534103fubFBUJTHN;a=array;for(loop=0;loopN;loop+)if(loop%5=0)printf(n); printf(%-5c,*a+);printf(n);printf(n*n);a=array;for(loop=0;loopN;loop+)if(A=*a)&(*an)printf(max=%d,m);else if(nm)printf(max=%d,n);else printf(m=n);main()int a,b,*p1,*p2;printf(please input a,b:);scanf(%d,%d,&a,&b);p1=&a;p2=&b;dx(*p1,*p2);#include stdio.hchange(int *p1,int *p2)int i;for(i=0;i=10)*p2=*p1;p1+;p2+;main()int array1=11,-5,18,115,21;int array25=0;change(array1,array2);printf(%-4d%-4d%-4d%-4d%-4dn,*array1,*(array1+1),*(array1+2),*(array1+3),*(array1+4);printf(%-4d%-4d%-4d%-4d%-4dn,*array2,*(array2+1),*(array2+2),*(array2+3),*(array2+4);结构体：不同的数据类型构成一个整体struct stuint num; char name20; char sex; float score;boy1,boy2; stu boy1,boy2;boy1.num=102;=Zhang ping; printf(input sex and scoren); scanf(%c %f,&boy1.sex,&boy1.score); boy2=boy1; printf(Number=%dnName=%sn,boy2.num,); printf(Sex=%cnScore=%fn,boy2.sex,boy2.score);【例】计算学生的平均成绩和不及格的人数。struct stu int num; char *name; char sex; float score;boy5= 101,Li ping,M,45, 102,Zhang ping,M,62.5, 103,He fang,F,92.5, 104,Cheng ling,F,87, 105,Wang ming,M,58,;main( ) int n=0,i,c=0; float max,ave,s=0; for(i=0;i5;i+) s+=boyi.score; if(boyi.score60) c+=1;pri