新编得程序函数调用总出错，求大神帮忙。。

#include
int my_str_len(void);
int print_char_array_values(void);
int char_array_reverse(void);
int main(void){
char arr[30];
int i;
char e,n,d;
while(3){
puts("Please provide a character string,don't type more than 30 elements:");
gets(arr);
/*if(arr[i]=='d' && arr[i-1]=='n' && arr[i-2]=='e')
break;*/
puts("The length of the character string is:");
my_str_len();
puts("The elements of the character string 1 are:");
print_char_array_values();
char_array_reverse();
puts("The elements of the character string 2 are:");
print_char_array_values();
}
return 0;
}

int my_str_len(void){
char arr[30];
int len=0;
int i=0;
while(arr[i]!='\0'){
i=i+1;
len=i;
puts("%d",len);
}
return len;
}

int print_char_array_values(void){
char arr[30];
int i=0;
while((arr[i]=getchar())!='\0'){
printf("%d",arr);
i=i+1;
}
return 0;
}

int char_array_reverse(void){
char arr[30];
int i=0;
int j=0;
char t;
while(arr[i]!='\0'){
i=i+1;
}
i=i-1;
while(j<i){
t=arr[i];
arr[i]=arr[j];
arr[j]=t;
i=i-1;
j=j+1;
}
return 0;
}

#include<stdio.h>
#include<stdlib.h>
int my_str_len(char arr[]);
int print_char_array_values(char* arr);
int char_array_reverse(char* arr);
int main(void){
    char arr[30];
    int i=0;
    char e,n,d;
    while(i<3){
        puts("Please provide a character string,don't type more than 30 elements:");
        gets(arr);
        /*if(arr[i]=='d' && arr[i-1]=='n' && arr[i-2]=='e')
        break;*/
        puts("The length of the character string is:");
        printf("%d\n",my_str_len(arr));
        puts("The elements of the character string 1 are:");
        print_char_array_values(arr);
        char_array_reverse(arr);
        puts("The elements of the character string 2 are:");
        print_char_array_values(arr);
        i++;
    }
    return 0;
}
int my_str_len(char* arr){
    //char arr[30];
    int len=0;
    int i=0;
    while(arr[i]!='\0'){
        i=i+1;
        len=i;
    }
    //puts("%d",len);
    return len; 
}
int print_char_array_values(char* arr){
    //char arr[30];
    int i=0;
    while(arr[i]!='\0'){
        printf("%c",arr[i]);
        i=i+1;
    }
    printf("\n");
    return 0;
}
int char_array_reverse(char* arr){
    //char arr[30];
    int i=0;
    int j=0;
    char t;
    while(arr[i]!='\0'){
        i=i+1;
    }
    i=i-1;
    while(j<i){
        t=arr[i];
        arr[i]=arr[j];
        arr[j]=t;
        i=i-1;
        j=j+1;
    }
    return 0;
}
```![图片说明](https://img-ask.csdn.net/upload/201511/16/1447668133_876073.jpg)