First,format
1.%d format
%[-]d left Justified
%[m]d Output with the field width specified by M, the number of bits in the data is less than M, the left-fill space
%[0m]d Output with the field width specified by M and the number of bits in the data is less than M, then the left 0
%[l]d Output Long Integer
%[-m]d left-aligned, ignoring 0 or spacesintnum = +;
printf"%-d", num);// +
printf"\n%10d", num);// +
printf"\n%010d", num);//0000001000
printf"\n%ld", num);// +
printf"\n%-10d", num);// +
2.%c format%[m]c with the field width specified in M, the number of bits in the data is less than M, and the Left fill space
%[0m]c Output with the field width specified by M, the number of bits in the data is less than M, and the left is 0
%[-m]c left-aligned, ignoring 0 or spaces printf ("\n%-c",'a');//a
printf"\n%5c",'a');//a
printf"\n%05c",'a');//0000a
printf"\n%-05c",'a');//a
3.%s format
%[-m]s output string in M column, left justified
%[m]s output string in M-column, right-aligned, left-fill space
%[0m]s output string in M-column, right-aligned, left-side complement 0
%[m.n]s the first n characters of the output string, in M-column, right-justified
%[.n]s First n characters of the output string, left justified
Charstr[ -] ="Hello";
printf"\n%-s", str);//Hello
printf"\n%10s", str);//Hello
printf"\n%010s", str);//00000hello
printf"\n%-10s", str);//Hello
printf"\n%.3s", str);//Hel
printf"\n%10.3s", str);//Hel
printf"\n%010.3s", str);//0000000hel
4.%f format
%[m][.n]f output data for M-column, decimal for n-bit, right-justified
%[-][m][.n]f output data is a total of M columns, fractional n bits, left justified
floatnum =10.356;
printf"\n%-8.2f", num);//10.36
printf"\n%08.2f", num);//00010.36
5.EGXC can be capitalized
//e Capital X output letter uppercase for EG output
printf"%d",Ten);//Ten
printf"\n%d",Ten);//D
printf"\n%c", $);//A
printf"\n%c",'A');//A
printf"\n%s","ABC");//ABC
printf"\n%s","ABC");//Empty
printf"\n%f",100000.0);//100000.000000
printf"\n%f",100000.0);//Empty
printf"\n%e",100000.0);//1.000000e+005
printf"\n%e",100000.0);//1.000000E+005
//g How to streamline how to output
printf"\n%g",100000.0);//100000
printf"\n%g",100000.0);//100000
printf"\n%g",1000000000.5555);//1E+009
printf"\n%o",Ten);// A
printf"\n%o",Ten);//O
printf"\n%x",Ten);//a
printf"\n%x",Ten);//A
6.printf function Considerations
1> If you want to output ", Need \" escape
2> If output% is required,
3>: Extra output items are not output when the format character is less than the output item
4>: When the format character is more than the output item, the result is an indeterminate value
printf"%\"");//"
printf"\n%%%");//%
printf"\n%d,%d",Ten, -, -);//10,20
printf"\n%d,%d,%d", -, -);//20,30,0
7.scanf function Considerations
1> additional format characters
* The input value is not assigned to the corresponding variable
L for input of long-shaped (32-bit platform input effect and%d) and double-precision real data
m specifies the width of the data and automatically captures the required length of data.
2>: Cannot specify precision when entering data
ii. File redirection
Reads the instruction from the text where the instruction is written and saves the result in another text.
cmd--> path-->exe file < input file name with instruction .txt> output TXT file name. txt
intCounts//number of
Charinstruct[ -];//instruction
scanf"%d%s", &counts, instruct);
Charstr[ -];
sprintf (str,"for/l%%i in (1,1,%d) do%s", counts,instruct);
System (STR);
System"Pause");
1. Enter tasklist in Notepad and save as Input.txt
Enter the path and EXE file name in cmd <input.txt>output.txt
Learn C day 5th (printf function, scanf function)
