如何直接比较数组中的第一个和第二个元素?

时间:2017-03-14 03:22:58

标签: c arrays if-statement for-loop

快速问题,每次来自char数组的字符不是后续字符时,我都会尝试打印新行。例如,如果text [i]是'a'而text [i + 1]不是'b',那么printf(“\ n”);

I / O的示例是:

 input: "abk123@XY"
 output: ab
         123
         XY

现在的输出是:

\n
\n
\n

这是我现在的代码:

void printNext(const char *t){
 //variable declerations 
 int i;

 for(i = 0; t[i] != '\0'; i++){

   if(t[i] != t[i + 1])//line in question, which isn't working 
      printf("\n");
    else if(t[i] >= '0' &&  t[i] <= '9')
        printf("%c",t[i]);
     else if (t[i] >= 'A'  && t[i] <= 'Z' )
          printf("%c",t[i]);
        else if(t[i] >= 'a'  && t[i] <= 'z')
            printf("%c",t[i]);


        }//end for

}//end printNext

主要功能是:

#include <stdio.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
void printNext(const char *);

int main(void){

  const char t[40] = "abk123@XY";

   printf("the original sequence of strings is: %s\n", text);
   printf("new string is: \n");
   printNext(t);


 }

3 个答案:

答案 0 :(得分:1)

从所有条件中删除其他内容。否则只检查'if'是否失败。但是你想要检查下一个条件,同时改变检查条件的顺序。

for(i = 0; t[i] != '\0'; i++){ 
     if(t[i] >= '0' &&  t[i] <= '9' )
          printf("%c",t[i]);
     if (t[i] >= 'A'  && t[i] <= 'Z' )
          printf("%c",t[i]);
     if(t[i] >= 'a'  && t[i] <= 'z')
          printf("%c",t[i]);
     if(t[i] + 1 != t[i + 1]) 
          printf("\n");
 }//end for

主要变化

int main(){
     const char t[80] = "abk123@XY";
     printf("the original sequence of strings is: %s\n", t);
     printf("new string is: \n");
     printNext(t);       
     return 0; 

}

答案 1 :(得分:1)

我建议喜欢这个

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

bool sameKindAndSeq(unsigned char a, unsigned char b){
    if(!a || !b || a + 1 != b)
        return false;
    if(islower(a))
        return islower(b);
    if(isupper(a))
        return isupper(b);
    if(isdigit(a))
        return isdigit(b);
    return false;
}

void printNext(const char *t){
    bool first = true;//flag of top of sequence of same kind
    for(; *t; ++t){
        if(first){
            if(sameKindAndSeq(*t, t[1])){
                putchar(*t);
                first = false;
            }
        } else {
            if(sameKindAndSeq(t[-1], *t)){
                putchar(*t);
            }
            if(!sameKindAndSeq(*t, t[1])){
                putchar('\n');
                first = true;
            }
        }
    }
}

int main(void){
    printNext("abk123@XY");
}

答案 2 :(得分:0)

@ minigeek的答案稍微更具可读性:

void printNext(const char *t)
{
    int i;
    int isdigit(int);
    int isupper(int);
    int islower(int);

    for(i = 0; t[i] != '\0'; i++){
        if (isdigit(t[i]))
            printf("%c",t[i]);
        if (isupper(t[i]))
            printf("%c",t[i]);
        if(islower(t[i]))
            printf("%c",t[i]);
        if(t[i] + 1 != t[i + 1])
            printf("\n");
    }
}