How to use sprintf function

One 、 Introduce

1、 This function is contained in stdio.h In the header file , Therefore need   #include <stdio.h>.
2、sprintf In peace, we often use printf The functions are very similar .sprintf Function to print to a string （ Note that the length of the string should be enough to accommodate the printed content , Otherwise, there will be a memory overflow ）, and printf Function prints out to the screen .sprintf Functions are often used to encapsulate specific strings like arrays .
3、sprintf Format of function ：
int sprintf( char *buffer, const char *format [, argument,…] );

Be careful sprintf The first parameter of the function is a character pointer , Therefore, when declaring , The array declaration is called character type ; If declared as another type , Attention switching .

Two 、 example sentence

example ：

1、

char str[20];   // Directly declared as a string array 

sprintf(str,"%d-%2d-%2d",year,month,day);

2、

unsigned char str[20];   // It is not directly declared as a string array , To convert 

sprintf((char*)str,"%d-%2d-%2d",year,month,day);