C Tutorial/Data Type/float Display
Содержание
- 1 %6f limits the output to only six digits
- 2 Displaying Floating-Point Data Types with printf: %f
- 3 %e displays numbers in scientific format.
- 4 %g displays a floating-point number in either the %f or %e (scientific) format, depending on which is shorter.
- 5 Printing floating-point numbers with floating-point conversion specifiers
- 6 To create precision with floating-point numbers
- 7 use the %E in printf() to display scientific-notation numbers
%6f limits the output to only six digits
<source lang="cpp">#include <stdio.h> main(){
printf("%6.1f", 123456.123456); printf("\n%6.2f", 123456.123456); printf("\n%6.3f", 123456.123456); printf("\n%6.4f", 123456.123456);
}</source>
123456.1 123456.12 123456.123 123456.1235
Displaying Floating-Point Data Types with printf: %f
<source lang="cpp">#include <stdio.h> main(){
float result; result = 3.123456; printf("The value of result is %f", result);
}</source>
The value of result is 3.123456
%e displays numbers in scientific format.
<source lang="cpp">#include <stdio.h> main(){
printf("%e", 123456.123456); printf("\n%e", 12345612345.6);
}</source>
1.234561e+05 1.234561e+10
%g displays a floating-point number in either the %f or %e (scientific) format, depending on which is shorter.
<source lang="cpp">#include <stdio.h> main(){
printf("%g", 123456.123456); printf("\n%g", 6.1);
}</source>
123456 6.1
Printing floating-point numbers with floating-point conversion specifiers
<source lang="cpp">#include <stdio.h> int main() {
printf( "%e\n", 1234567.89 ); printf( "%e\n", +1234567.89 ); printf( "%e\n", -1234567.89 ); printf( "%E\n", 1234567.89 ); printf( "%f\n", 1234567.89 ); printf( "%g\n", 1234567.89 ); printf( "%G\n", 1234567.89 ); return 0;
}</source>
1.234568e+06 1.234568e+06 -1.234568e+06 1.234568E+06 1234567.890000 1.23457e+06 1.23457E+06
To create precision with floating-point numbers
%.2f displays only two zeroes after the decimal point.
<source lang="cpp">#include <stdio.h>
main(){
printf("%.1f", 3.123456); printf("\n%.2f", 3.123456); printf("\n%.3f", 3.123456); printf("\n%.4f", 3.123456); printf("\n%.5f", 3.123456); printf("\n%.6f", 3.123456);
}</source>
3.1 3.12 3.123 3.1235 3.12346 3.123456
use the %E in printf() to display scientific-notation numbers
<source lang="cpp">#include <stdio.h>
int main() {
float lightyear = 5.878E12; float jupiter = 483400000; float distance; distance = jupiter/lightyear; printf("Jupiter is %E light years from the sun.\n",distance); return(0);
}</source>
Jupiter is 8.223886E-005 light years from the sun.