Use in printf (C language)

Use in printf (C language)

# Include
 
  
#include

int main (int argc, const char * argv []) {

    // Shaping output
    printf (% d,% d, 3,4);
    printf (
);
    // The width of characters output by shaping,% md
    printf (% 4d,% 4d, 3,4);
    printf (
);

    // Long integer format output
    printf (% ld,% ld, (long) 3, (long) 4);
    printf (
);
    // Long shape can also set the output character width
    printf (% 8ld,% 8ld, (long) 3, (long) 4);
    printf (
);


    // Output% o in octal format
    int a = -1;
    printf (% d,% o, a, a);
    printf (
);
    printf (% d,% 13o, a, a); // Set the output width of characters
//-1 is stored in memory (exists in two's complement): eg: 111111111 (the first bit is the sign bit)
    printf (
);

    // X symbol output in hexadecimal
    int b = -1;
    printf (% x,% o,% d, b, b, b);
    
    printf (
);

    // u is unsigned output
    int c = -1;
    unsigned int d = 65535;
    printf (% x,% o,% d,% u, c, c, c, c);
    printf (
);
    printf (% x,% o,% d,% u, d, d, d, d);
    
    printf (
);

    // c format character, output one character
    char e = 'a';
    printf (% c,% d, e, e);
    
    printf (
);

    // s format character, used to output a string
// char f [] = china;
// prinf (% s, f);
#warning Problem with output string
    
    // f format character, used to output real numbers (including: single precision, double precision), output in decimal form
    // 1,% f format character, does not specify the width of the field, it is automatically specified by the system, so that all integer parts are output, and 6 decimal places are output. Note: Not all digits in the output numbers are significant digits, and the single-precision real number significant digits are generally 7 digits. The double-precision significant digit is 16 digits, giving 6 decimal places.
// float x, y;
// x = 11111111.111; y = 22222222,222;
// printf (% f
, x + y); // It can be seen from the result that only 7 bits are valid.
    double x, y;
    x = 11111111.111; y = 22222222.222;
    printf (% f
, x + y);
    // 2,% m.nf, specify the output data for occupying m columns, where n decimal places, if the value is greater than m, there will be no spaces on the left.
    // 3.% -M.nf is basically the same as% m.nf, except that the output value is leaning to the left and padding to the right.
    

    // symbol e, output as an exponent
    // 1,% e, do not specify the width occupied by the output data, and the number of decimal places in the number part. Some c compiler systems automatically indicate that the number given is 6 decimal places, and 5 digits of the exponent. eg: +002)
    printf (% e, 12389.454566); // and this system is the default stack of 4 bits
    printf (
);

    //%m.ne and% -m.ne, m, n,-are the same as before.
    double f = 123.456;
    printf (% e% 10e% 10.2e% .2e% -10.2e, f, f, f, f, f);
    printf (
);

    // The format character g is used to output real numbers. It automatically selects the f format or the e format according to the size of the number.
    double g = 123.456;
    printf (% f% e% g, g, g, g);
    printf (
);

    double h = 1234567123.456;
    printf (% f% e% g, h, h, h);

    
    // Note: A format character starts with% and ends with one of the above format characters. You can insert additional modifiers in the middle, which are actually ordinary characters.
// printf (c =% cf =% fs =% s, c, f, s); // In fact, f = is an ordinary character
    printf (
);

    // output% symbol
    printf (% f %%, 1.0 / 3);
    
    getchar ();
    return 0;
}  

The following figure shows the output of some corresponding format symbols:

 

The following is the Escape Character ""