Sprintf's statement is that

int sprintf(char *dst，const char * format_str...);

Its function is to input parameters ... import dst according to the requirements of format_str.

You need to use format_str according to the type of number.

For example, the integer (int) is used as follows

sprintf(buf，" %d "，a)；

If a is 123, then the string in buf is "123".

Common types of numbers are:

1 short, output band% h；;

2 long, output with %ld;

3 floating-point type, output with %f;

4 Double precision with output of %lf.