C中的指針在“類型”之前缺少“;”

Question

我是C語言的新手。我正在在線上這堂課，很難獲得幫助。 我知道這個問題已經被問到並回答了我的惡心，但我似乎無法弄清楚該函數中需要聲明什么。

編輯：我正在使用Visual Studio 2008。

此處的功能旨在使整個字符串變為小寫並計算所述字符串中的單詞

錯誤發生在main函數調用中，但我認為真正的問題出在函數本身上。
例子：

   char lowercase( char *stringToLower)
    {   
        int i; //local counter i

        for (i = 0; i < 100; i++)
         stringToLower[i] = toupper(stringToLower[i]);
        return i;

    }// end make LOWERcase

還有這個

void countWordsLower( char *stringToLower)
{
    // define local variables 
    char *tokenPtr;
    int i;
    int counter = 0;

    printf( "\nThe string to be tokenized is:\n");
    puts( stringToLower );

    tokenPtr = strtok( stringToLower, " \n"); 

    // tokenize until tokenPtr becomes NULL
    while ( tokenPtr ) 
    {
        ++counter;
        //increment counter
        tokenPtr = strtok( NULL, " \n" ); 
        // gets next token

    } // end while 

    printf( "\nThe total number of words is %d\n\n", counter );

} // end countWords LOWER

這些是他們的原型

void countWordsLower ( char *stringToLower );
char lowercase ( char *stringToLower ); 

上下文中的整個程序如下：

#include <stdio.h>
#include <string.h>
#include <ctype.h>

// Function prototypes 
void concatenate ( char *stringFirst, char *stringSecond );
char lowercase ( char *stringToLower ); 
char uppercase ( char *stringToUpper );
void countWordsLower ( char *stringToLower );
void countWordsUpper ( char *stringToUpper );
void twoStrings ( char *stringFirst, char *stringSecond );

int main (void)
{
    // initialize variables 
    int menuOption; // user choice
    int tokens; // holds return value from tokenize 
    char stringToLower [100]; // 99 character string
    char stringToUpper [100]; // 99 character string
    char stringFirst [100]; //first string able to hold 99 chars
    char stringSecond [100];//second string able to hold 99 chars

    do 
    {
        printf ( "\n\nWelcome!\n" );
        printf ( "\nEnter 1 for Concatenate Two Strings\n" );
        printf ( "\nEnter 2 for Change to LOWER Case with Word Count" );
        printf ( "\nEnter 3 for Change to UPPER Case with Word Count" );
        printf ( "\nEnter 4 to Terminate program" );

        printf ( "\n\nPlease enter your selection: " );
        scanf( "%d", &menuOption );
        // list menu options
        switch (menuOption)
        {
            case 1:
                //Concatenate Two Strings
                printf( "\nThis function will concatenate two strings into a third\n");
                printf( "Enter first string:\n\n\t");
                gets( stringFirst );

                printf( "Enter second string:\n\n\t" );
                gets( stringSecond );

            //function to concatenate
            twoStrings( stringFirst, stringSecond );
                break;
                //end choice one

            case 2:
                //Change to LOWER Case with Word Count
                printf( "\nThis function will change an entire string to LOWER case\n");
                printf( "\nand count the number of words!\n");
                printf( "Enter string:\n\n\t");
                gets( stringToLower );

                //function to change to lowercase
                lowercase( char &stringToLower );

                //function to count number of words
                countWordsLower( char &stringToLower );

                break;

            case 3:
                //Change to UPPER Case with Word Count
                printf( "\nThis function will change an entire string to UPPER case\n");
                printf( "\nand count the number of words!\n");
                printf( "Enter string:\n\n\t");
                gets( stringToUpper );

                //function to change to uppercase
                uppercase( char &stringToUpper);

                //function to count number of words
                countWordsUpper( char &stringToUpper);
                break;

            case 4:
                //End Program
                printf( "\nThank You!\n Come Again!\n\n" );
                break;

            default:
                printf ( "\nWhoops!  Try a number 1,2,3 or 4!\n" );

        }//end switch

    }// end do

    while (menuOption != 4);


}// end main
void concatenate ( char *stringFirst, char *stringSecond)
{
    char stringThird[200]; 


    printf( "\nString ois %s\nString two is %s\n", stringFirst, stringSecond );


    // concatenate stringFirst to stringSecond with space 
    strcpy(stringThird, stringFirst);
    strcat(stringThird, " ");
    strcat(stringThird, stringSecond);


    printf( "\nTogether ... %s\n\n", stringThird );


} // end concatenate

//function to make LOWERcase
char lowercase( char *stringToLower)
{   
    int i; //local counter i

    for (i = 0; i < 100; i++)
     stringToLower[i] = toupper(stringToLower[i]);
    return i;

}// end make LOWERcase


    // function to count number of words
    // in string that was made LOWERcase
void countWordsLower( char *stringToLower)
{
    // define local variables 
    char *tokenPtr;
    int i;
    int counter = 0;

    printf( "\nThe string to be tokenized is:\n");
    puts( stringToLower );

    tokenPtr = strtok( stringToLower, " \n"); 

    // tokenize until tokenPtr becomes NULL
    while ( tokenPtr ) 
    {
        ++counter;
        //increment counter
        tokenPtr = strtok( NULL, " \n" ); 
        // gets next token

    } // end while 

    printf( "\nThe total number of words is %d\n\n", counter );

} // end countWords LOWER

//function to make UPPERcase
char uppercase( char *stringToUpper )
{
    int i; //local counter i

    for (i = 0; i < 100; i++)
        stringToUpper[i] = toupper(stringToUpper[i]);
    return i;
}// end make UPPERcase

    // function to count number of words
    // in string that was made UPPERcase
void countWordsUpper( char *stringToUpper )
{
    // define local variables 
    char *tokenPtr;
    int i;
    int counter = 0;


    printf( "\nThe string to be tokenized is:\n");
    puts( stringToUpper );


    tokenPtr = strtok( stringToUpper, " \n"); 


    // tokenize until tokenPtr becomes NULL 
    while ( tokenPtr ) 
    {
        ++counter;
        //increment counter
        tokenPtr = strtok( NULL, " \n" );
        // gets next token 


    } // end while 

    printf( "\nThe total number of words is %d\n\n", counter );


} // end countWords UPPER

以下是在一個C編譯器中編譯以上代碼所導致的錯誤：

main.c:58:38: error: expected ')'
                char lowercase( char &stringToLower );
                                     ^
main.c:58:31: note: to match this '('
                char lowercase( char &stringToLower );
                              ^
main.c:58:22: error: conflicting types for 'lowercase'
                char lowercase( char &stringToLower );
                     ^
main.c:7:6: note: previous declaration is here
char lowercase ( char *stringToLower ); 
     ^
main.c:61:44: error: expected ')'
                void countWordsLower( char &stringToLower );
                                           ^
main.c:61:37: note: to match this '('
                void countWordsLower( char &stringToLower );
                                    ^
main.c:61:22: error: conflicting types for 'countWordsLower'
                void countWordsLower( char &stringToLower );
                     ^
main.c:9:6: note: previous declaration is here
void countWordsLower ( char *stringToLower );
     ^
main.c:73:38: error: expected ')'
                char uppercase( char &stringToUpper);
                                     ^
main.c:73:31: note: to match this '('
                char uppercase( char &stringToUpper);
                              ^
main.c:73:22: error: conflicting types for 'uppercase'
                char uppercase( char &stringToUpper);
                     ^
main.c:8:6: note: previous declaration is here
char uppercase ( char *stringToUpper );
     ^
main.c:76:44: error: expected ')'
                void countWordsUpper( char &stringToUpper);
                                           ^
main.c:76:37: note: to match this '('
                void countWordsUpper( char &stringToUpper);
                                    ^
main.c:76:22: error: conflicting types for 'countWordsUpper'
                void countWordsUpper( char &stringToUpper);
                     ^
main.c:10:6: note: previous declaration is here
void countWordsUpper ( char *stringToUpper );
     ^

改變...再次

                //function to change to lowercase
                lowercase( stringToLower );

                //function to count number of words
                countWordsLower( stringToLower );

對於任何仍在關注最終代碼的人，因為我最終將其固定為

#ifdef _MSC_VER
#define _CRT_SECURE_NO_WARNINGS
#endif
#include <stdio.h>
#include <string.h>
#include <ctype.h>

// Function prototypes 
void concatenate ( char *stringFirst, char *stringSecond );
char lowercase ( char *stringToLower ); 
char uppercase ( char *stringToUpper );
void countWordsLower ( char *stringToLower );
void countWordsUpper ( char *stringToUpper );

int main (void)
{
    // initialize variables 
    int menuOption; // user choice
    int tokens = 0; // holds return value from tokenize 
    char stringToLower [100]; // 99 character string
    char stringToUpper [100]; // 99 character string
    char stringFirst [100]; //first string able to hold 99 chars
    char stringSecond [100];//second string able to hold 99 chars

    do 
    {
        printf ( "\n\nWelcome!\n" );
        printf ( "\n""*Concatenate*""" );
        printf ( "\nEnter 1 for Concatenate Two Strings\n" );
        printf ( "\n""*Change Case*""" );
        printf ( "\nEnter 2 for Change to LOWER Case with Word Count" );
        printf ( "\nEnter 3 for Change to UPPER Case with Word Count\n" );
        printf ( "\n""*Exit*""" );
        printf ( "\nEnter 4 to Terminate program" );

        printf ( "\n\nPlease enter your selection: " );
        scanf( "%d", &menuOption );
        _flushall();

        // list menu options
        switch (menuOption)
        {
            case 1:
                //Concatenate Two Strings
                printf( "\nThis function will concatenate two strings into a third\n");
                printf( "\nEnter first string:  ");
                fgets( stringFirst, 99, stdin );
                strtok( stringFirst, "\n" );
                printf( "\nEnter second string:  " );
                strtok( stringSecond, "\n" );
                fgets( stringSecond, 99, stdin );

            //function to concatenate
            concatenate ( stringFirst, stringSecond );
                break;
                //end choice one

            case 2:
                //Change to LOWER Case with Word Count
                printf( "\nThis function will change an entire string to LOWER case\n");
                printf( "and count the number of words!\n");
                printf( "\nEnter string:  ");
                fgets( stringToLower, 99, stdin );
                printf( "\nThe original string is:  " );
                printf( "%s", stringToLower );


                //function to change to lowercase
                lowercase( stringToLower);

                //function to count number of words
                countWordsLower( stringToLower);

                break;

            case 3:
                //Change to UPPER Case with Word Count
                printf( "\nThis function will change an entire string to UPPER case\n");
                printf( "and count the number of words!\n");
                printf( "\nEnter string:  ");
                fgets( stringToUpper, 99, stdin );
                printf( "\nThe original string is:  " );
                printf( "%s", stringToUpper );

                //function to change to uppercase
                uppercase( stringToUpper );

                //function to count number of words
                countWordsUpper( stringToUpper );
                break;

            case 4:
                //End Program
                printf( "\nThank You!\n Come Again!\n\n" );
                break;

            default:
                printf ( "\nWhoops!  Try a number 1,2,3 or 4!\n" );

        }//end switch

    }// end do

    while (menuOption != 4);


}// end main
void concatenate ( char *stringFirst, char *stringSecond )
{
    char stringThird[200]; 


    printf( "\n\nString One is: %s\nString Two is: %s\n", stringFirst, stringSecond );


    // concatenate stringFirst to stringSecond with space 
    strcpy(stringThird, stringFirst);
    strcat(stringThird, " / ");
    strcat(stringThird, stringSecond);


    printf( "Together they read:  %s", stringThird );


} // end concatenate

//function to make LOWERcase
char lowercase( char *stringToLower )
{   
    int i; //local counter i

    for (i = 0; i < 100; i++)
     stringToLower[i] = tolower(stringToLower[i]);
    return i;

}// end make LOWERcase


    // function to count number of words
    // in string that was made LOWERcase
void countWordsLower( char *stringToLower )
{
    // define local variables 
    char *tokenPtr;
    int i = 0;
    int counter = 0;

    printf( "\nThe adjusted string is:  ");
    puts( stringToLower );

    tokenPtr = strtok( stringToLower, " \n"); 

    // tokenize until tokenPtr becomes NULL
    while ( tokenPtr ) 
    {
        ++counter;
        //increment counter
        tokenPtr = strtok( NULL, " \n" ); 
        // gets next token

    } // end while 

    printf( "The total number of words is %d\n", counter );

} // end countWords LOWER

//function to make UPPERcase
char uppercase( char *stringToUpper )
{
    int i = 0; //local counter i

    for (i = 0; i < 100; i++)
        stringToUpper[i] = toupper(stringToUpper[i]);
    return i;
}// end make UPPERcase

    // function to count number of words
    // in string that was made UPPERcase
void countWordsUpper( char *stringToUpper )
{
    // define local variables 
    char *tokenPtr;
    int i = 0;
    int counter = 0;


    printf( "\nThe adjusted string is:  ");
    puts( stringToUpper );


    tokenPtr = strtok( stringToUpper, " \n"); 


    // tokenize until tokenPtr becomes NULL 
    while ( tokenPtr ) 
    {
        ++counter;
        //increment counter
        tokenPtr = strtok( NULL, " \n" );
        // gets next token 


    } // end while 

    printf( "The total number of words is %d\n", counter );


} // end countWords UPPER

順便說一句，感謝您的所有答復和支持！

Answer 1

您（不是很）在main的中間聲明函數，而不是調用它們。 例如，當您說：

char lowercase( char &stringToLower );

//function to count number of words
void countWordsLower( char &stringToLower );

這些是（無效的）函數原型。 你想說：

lowercase( stringToLower );
countWordsLower( stringToLower );

Answer 2

在此代碼段中，您有錯：

//function to change to uppercase
char uppercase( char &stringToUpper);

//function to count number of words
void countWordsUpper( char &stringToUpper);
break;

調用函數時， 既不包含返回類型，也不包含參數的類型。 （那些僅在聲明和定義函數時使用，而在使用它們時不使用）

代碼應為：

//function to change to uppercase
uppercase(stringToUpper);

//function to count number of words
countWordsUpper(stringToUpper);
break;