sprintf函数的用法和注意事项,c++sprintf函数的用法

注意

字符串格式化时不要，输入和输出参数不要使用同一个字符数组。
springt函数处理流程分析：

输入和输出参数不同sprintf(str2, “ab%s”,str)：

输入和输出参数相同sprintf(str, “ab%s”,str)：

示例 #include <stdio.h>int main(){char str[10] = "0123456789";char str2[10] = "";str[0] = 0;str[1] = 0;str[2] = 0;str[3] = 0;for(int i = 0;i<10;i++){printf("1-str_c[%d] = %cn",i,str[i]);}printf("1-str = %sn",str);//str格式化到str2sprintf(str2, "ab%s",str);for(int i = 0;i<10;i++){printf("2-str2_c[%d] = %cn",i,str2[i]);}printf("2-str2 = %sn",str2);for(int i = 0;i<10;i++){printf("3-str_c[%d] = %cn",i,str[i]);}printf("3-str = %sn",str);//str格式化到str（注意：这个地方输出结果）sprintf(str, "ab%s",str);for(int i = 0;i<10;i++){printf("4-str_c[%d] = %cn",i,str[i]);}printf("4-str = %sn",str); return(0);}

下面是打印结果：

1-str_c[0] = 1-str_c[1] = 1-str_c[2] = 1-str_c[3] = 1-str_c[4] = 41-str_c[5] = 51-str_c[6] = 61-str_c[7] = 71-str_c[8] = 81-str_c[9] = 91-str = 2-str2_c[0] = a2-str2_c[1] = b2-str2_c[2] = 2-str2_c[3] = 2-str2_c[4] = 2-str2_c[5] = 2-str2_c[6] = 2-str2_c[7] = 2-str2_c[8] = 2-str2_c[9] = 2-str2 = ab3-str_c[0] = 3-str_c[1] = 3-str_c[2] = 3-str_c[3] = 3-str_c[4] = 43-str_c[5] = 53-str_c[6] = 63-str_c[7] = 73-str_c[8] = 83-str_c[9] = 93-str = 4-str_c[0] = a4-str_c[1] = b4-str_c[2] = a4-str_c[3] = b4-str_c[4] = 4-str_c[5] = 54-str_c[6] = 64-str_c[7] = 74-str_c[8] = 84-str_c[9] = 94-str = abab