char ch1[] = "abc";
char ch2[] = "def";
char ch3[20];
int i = 0;
int k = 0;
while (ch1[i] != ‘\0‘)
{
ch3[i] = ch1[i];
i++;
}
while (ch2[k] != ‘\0‘)
{
ch3[k + i] = ch2[k];
k++;
}
ch3[k + i] = ‘\0‘;
printf("%s\n", ch3);
注意: 字符串和字符数组到区别 字符串结尾带有‘\0‘ 字符数组没有‘\0‘
原文：https://www.cnblogs.com/mayichen0823/p/10163885.html