C language final review questions

Catalog

One 、 choice question

Two 、 Completion

3、 ... and 、 Reading program , Write the result

Four 、 Correct the wrong questions

5、 ... and 、 Programming questions

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One 、 choice question

1. The following is not C The characteristic of language is (  C  )

A.C The language is simple 、 compact                  B． Be able to program complex functions

C. C Language can directly operate the hardware     D．C Good language portability

2. The narrative is wrong ：                                                 （     D   ）

A. One C The source program can consist of one or more functions

B. One C The source program must contain a MAIN function

C. C The basic unit of a program is a function

D. C In the program , Note description can only be after one statement

3． One c The execution of the program is from ( A   ).

A．main(    ) Function to , until main(    ) End of the function

B． The first function starts , Until the end of the last function

C. Start with the first statement , Until the end of the last statement

D．main(    ) Function to , Until the end of the last function

4.   The types of known variables are described as follows ：

int  k, a, b;

unsinged long w=5;

double x=1.42;

Then the following does not meet Ｃ Language grammar is                                    （       A ）

A.  x%(-3)

B.  w+=-2;

C.  k=(a=2,b=3,a+b)

D.  a+=a-=(b=4)*(a=3)

5. If the following variables are all integer , And num=sum=7; Then the expression is evaluated sum=num++,sum++,++num after sum The value of is (   B )

A.7          B.8         C.9                D.10

6.  When the form of input data is ：25,13,10 < enter > when , The output of the following program is            （    D    ）

main()

{int x,y,z;

      scanf(“%d%d%d”,&x,&y,&z);

      printf(“x+y+z=%d\n”,x+y+z);

}

A. x+y+z=48

B. x+y+z=35

C. x+z=35

D. Uncertain value

7. sizeof(float) yes (  B  ).

A. A double expression               B. An integer expression

C. A function call                     D. An illegal expression

8.  It can be expressed correctly “ When x The value of the [1,10] and [200,210] The range of is true , Otherwise it is false ” The expression of （   C   ）

A. (x>=1)&&(x<=10)&&(x.>=200)&&(x<=210)

B. (x>=1)││(x<=10) ││(x.>=200) ││(x<=210)

C. (x>=1) &&(x<=10) ││(x.>=200) &&(x<=210)

D. (x>=1)││(x<=10)&& (x.>=200) ││(x<=210)

analysis ： according to C Priority of language operators ,＆＆ Above ||, So we have to calculate first “ And ” Count again “ or ”, The answer for :C

9. Set description ： char w; int x; float y; double z; Expression w*x+z-y The data type of the value is (  D   ).

A.float               B.char               C.int                 D.double.

10. Please read the following procedure ：

#include <stdio.h>

main( )

 { int  a=5 , b=0 , c=0;

  if (a=b+c)  printf(“* * *\n”);

  else   printf(“$ $ $\n”);  }

The above procedure                                                       （D ）

A. There are syntax errors that cannot be compiled

B. It can be compiled but not directly connected

C. Output * * *

D. Output $ $ $

11. The following statement is correct (   D ).

A. The input can be a real constant ( Variable ), Such as scanf(“%f”,3.5);

B. Only format control , No entries , It can also make correct input , Such as scanf(“a=%d,b=%d”); Missing variable

C. When entering a real data , The format control part shall specify the number of digits after the decimal point , Such as scanf(“%4.2f”,&f);

D. When entering data , The address of the variable must be specified , Such as scanf(“%f”,&f);

12. C In language while and do-while The main difference between loops is .                            （    A    ）

A. do-while The body of the loop is executed unconditionally at least once

B. while Cycle control condition ratio do-while The cycle control conditions are strict

C. do-while Allow transfer from the outside to the circulation body

D. do-while Allow transfer from the outside to the circulation body

13. Known letters A Of ASCII Code is 65, The execution result of the following procedure is (  D  ).

#include<stdio.h>

main()

{

 char c1='A',C2='Y';

 printf("%d,%d\n",c1,c2);

A.A,Y         B.65,65          C.65,90              D.65,89

14.  stay c In language , When referencing array elements , The data type of its array subscript is allowed to be .            （    C   ）

A. integer constants

B. Integer expression

C. Integer constant or integer expression

D. Any type of expression

15. The data type of the operand on both sides of the logical operator (    D).

 A. Can be 0 or 1

 B. Can only be 0 Or not 0 Positive numbers

 C. Only integer or character data

 D. It can be any kind of data

16. The following correct form of function definition is .                                           （ A  ）

A. double fun(int x,int y)

B. double fun(int x;int y)

C. double fun(int x,int y);

D. double fun(int x,y);

17. The following is not true if The sentence form is                                              (  C  ).

A.if(x＞y&&x!=y);

B.if(x＝＝y)x Ten ＝y;

C.if(x ! ＝y)scanf(“％d”,&x) e1se scanf(”％d,&y);

D.if(x＜y){x twenty ;y twenty ;}

18.  With definition ：int n=0,* p=&n, q;  In the following options , The correct assignment statement is                ( D    ）

A.  p=1 B.  *q=2 C.  *q=p D.  *p=5

19. Read the following procedure

main()

{

int a=5,b=0,c=0;

if(a=b+c) printf(“***\n”);

else     printf(“$$$\n”);

}

The above procedure (   A).

A. Syntax errors cannot be compiled                      B. It can be compiled but not connected

C. Output ***                                   D. Output $$$

20.  The standard input file of the system refers to                                               （ A  ）

A.  keyboard

B.  Monitor

C.  floppy disk

D.  Hard disk

Two 、 Completion

1. stay C In language , The combining direction of unary operators （ Operation direction ） yes _____ From right to left _______.
2. expression 8/4*(int)2.5/(int)(1.25*3.7+2.3) The data type of the value is （   int type （ integer ）         ）.
3. Loop statement for(;;) printf("OK \n"); and do { printf("OK\n");} while(0); Execute the cycle , The number of cycles is ______ Infinite _________ and __________1_____.
4. 4. if x by int Type variable , Then execute the following statement x The value of is （    -14     ）

x=7;

x+=x-=x+x;

1. . The three basic structures of structured programming are ： Selection structure 、 Loop structure and ____ The order structure ____________.
2.   Yes int a=3,b=4,c=5; Expression a||b+c&&b= =c The value of is （   1     ）.
3. Set macro definition #define D (x) x/x, Then reference D(2+3) The last value is ______6_________.
4.   stay C In language , The storage order of two-dimensional array elements in memory is （    By line       ）.
5. If there is a definition ：double x[3][5]; be x The lower limit of the row subscript in the array is （   0   ）, The upper limit of column subscript is （ 4     ）.
6. C Language policy , The starting point of the executable program is （ The main function （main function ）        ）.

3、 ... and 、 Reading program , Write the result

1. #define   PRICE   30

#include <stdio.h>

void main()

{

     int num,total;

     num=10;

     total=num*PRICE;

     printf("total=%d\n",total);

}

The output of the above program is   total= 300   .

2. #include "stdio.h"

void main( )

{ int a,m=0,n=0,k=0;

 scanf("%d",&a);

switch(a)

{ case 1: m++; break;

case 2:

case 3: n++; break;

case 4:

case 5: k++;

}

printf("%d,%d,%d\n",m,n,k);

}

Type... From the keyboard 1, The result of writing the program is  m=1,n=0,k=0                                          

3.  The running result of the following program is ：AB

#include <stdio.h>

void main()

{  char a;

    a='B';

    putchar('\101'); putchar(a);

}

4.  When the following program runs, enter... From the keyboard 15,20, The running result is __a=15,b=20_____________.

#include "stdio.h"

void main( )

{ int a,b,t;

  t = 0;

scanf("%d,%d",&a,&b);

if (a>b)

{ t = a ;a = b ;b = t ;}

printf("a=%d,b=%d\n",a,b) ;

}

5．#include "stdio.h"

void main( )

{ int i,m,p,a[10]={9,8,7,6,1,3,5,18,2,4};

    m=a[0];

    p=0;

    for(i=1;i<10;i++)

     if (a[i]<m)

{ m=a[i]; p=i;}

      printf("%d,%d\n",m,p);  

   }

The output of the above program is        m=1,p= 4       

Four 、 Correct the wrong questions

1. #include <stdio.h>

void  main( )

{ int x , y ;

   scanf(“%d,%d”, &x, &y); 

   if (x>y;)

   printf(“%d”,x);

   else

   printf(“%d”,y);

}

Change it to ： #include <stdio.h>

void  main( )

{ int x , y ;

   scanf (“%d,%d”, &x, &y); 

   if (x>y)

   printf(“%d”,x);

   else

   printf(“%d”,y);

                          If The semicolon goes behind                                  

2 . #include <stdio.h>

void main()

{   char  c;

    c=gets( );

    putchar(c);

}

Change it to ：

#include <stdio.h>

void main()

{ char  c;

    c=getchar( );

    putchar(c);

}      gets Change it to getchar

analysis ：gets The function is to input a line of string , End with a carriage return , And the Enter key will be filtered out , Will not be read into the string , and getchar The function is to read a character , Including the Enter key will also be read as a character

3. #include <stdio.h>

void main()

{ int max(int x,int y);

   int a,b,c;

   scanf("%d,%d",&a,&b);

   c=max(a,b);

   printf("Max is %d",c);

}

max(int x, int y)

{ int z;

   z=x>y?x:y;

   return(x);

}

Change it to ：

 #include <stdio.h>

void main()

{ int max(int x,int y);

   int a,b,c;

   scanf("%d,%d",&a,&b);

   c=max(a,b);

   printf("Max is %d",c);

}

max(int x, int y)

{ int z;

   z=x>y?x:y;

   return(z);

}

                x Change it to z                                           

5、 ... and 、 Programming questions

1． There is a function

 

Make a program , Enter a x value , Output y value .（7 branch ）

#include<stdio.h>
int main()
{
	int x,y;
	printf(" Please enter x:");
	scanf("%d",&x);
	if(x<0)
		y=-1;
	else if(x==0)
		y=0;
	else
		y=1;
	printf("y=%d",y);
}

2. Find the sum of elements with even subscripts in a one-dimensional array , Completion procedure                         

   #include "stdio.h"

void main( )

{ int  i,  sum=0   ;            /* Please initialize sum by 0 */

int  a[]={2,3,4,5,6,7,8,9};

for(i=0; i<8; i=i+2  )         /* Please supplement the complete loop statement */

sum+=a[i];                  /* Please use sum Save the sum of the elements with even subscripts in the array */

printf("sum=%d\n",sum);

}

3． Type... From the keyboard 20 Students C language achievement , Calculate the grade average , And the output .

#include<stdio.h>
int main()
{   
 int i; 
 double a[20],sum=0.0,ave;
 printf(" Please enter 20 Students' grades ：\n");               
    for(i=0;i<20;i++)
    { 
  scanf("%lf",&a[i]);
     sum+=a[i];
 }
 ave=sum/20.0;
 printf(" The average score is ：%.2lf",ave);
 return 0;
}

5.  Program and print out all “ Narcissistic number ”, The so-called narcissus number refers to a 3 digit , The sum of the cubes of the numbers is equal to the number itself . Such as 153=13+33+53.

Programming tips ： Define a variable as a loop variable , Redefine 3 Variables store each number of three digits , Split a three digit number into one digit in the loop body 、 ten 、 After 100, judge whether the value of the cyclic variable is the number of daffodils , Output if yes , Otherwise, it will not output . The basic structure of the program is ：

 #include "stdio.h"

  void main( )

{   

int   a,b,c ,j             ;                  /* Definition 4 An integer variable */

    for( j=100; j<=999; j++ )

{  

a= j%10             ; 　　　　 　      /* Separate out the hundreds */

       b=  j/10%10            ;　　　  　        /* Separate out the tens */

       c=___j/100_____ _  __ ;　　　            /* Separate out the single digits */

      if(j==a*a*a+b*b*b+c*c*c)

      printf(“j=%d”,j) ;

    }

    printf("\n");

  }

6． Find the maximum and minimum values of elements in a two-dimensional array    

  4 ,4,34

37,3,12,

5, 6,  5

#include<stdio.h>
int main()
{
   int a[3][3]={
   {4,4,34},{37,3,12},{5,6,5}};
   int max=a[0][0],min=a[0][0],i,j,t;
   for(i=0;i<=2;i++)
   for(j=0;j<=2;j++)
   {
    if(a[i][j]<min)
    {
     t=a[i][j];
     a[i][j]=min;
     min=t;
 }
 if(a[i][j]>max)
    {
     t=a[i][j];
     a[i][j]=max;
     max=t;
 }
   }
   printf("min=%d\nmax=%d",min,max);
}