C.char字符串的拼接和const char*的轉換

C里沒有String類型

要用char[]來代替String的職能

上代碼：

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

int main(void)
{
    const char *p1;
    char str1[] = "hello";
    char str2[] = " world";
    char newStr[50] = "";
    strcat(newStr, "good,"); //直接把字符串添加到newStr
    strcat(newStr, str1);    //str1添（追）加到newStr
    strcat(newStr, str2);    //str2添（追）加到newStr
    p1 = newStr;             //char可以直接賦值給const char*
    printf("p1: %s\n", p1);
    printf("p1.length(err): %d\n", sizeof(p1)); //這個獲取的長度並不是真實字符串長度
    printf("p1.length: %d\n", getLength(p1));
    printf("str1.length: %d \n", sizeof(str1)); //(含字符串尾部的結束符\0，所以長度要加1)
    printf("str2.length: %d\n", sizeof(str2));
    printf("newStr.length: %d \n", sizeof(newStr)); //(按實際定義的數組長度)
｝

運行結果：

p1: good,hello world
p1.length(err): 8
p1.length: 16
str1.length: 6
str2.length: 7
newStr.length: 50