The article directories

  • Floating point types
    • 1. Basic introduction
    • 2. Case Demonstration:
    • 3. Classification of floating point types
    • 4. 4. Smart refrigerator
    • 5. Floating point usage details

Floating point types

1. Basic introduction

C floating-point types can represent a decimal number, such as 123.4, 7.8, 0.12, and so on

2. Case Demonstration:

3. Classification of floating point types

4. 4. Smart refrigerator

  1. A simple explanation of how floating-point numbers can be stored in a machine,Floating point = sign bit + exponent bit + mantissa bit , Floating point numbers are myopic values
  2. Mantissa may be lost, resulting in loss of accuracy.

5. Floating point usage details

  1. Floating-point constants default todoubleType, the statementfloatType constant, must be followed by ‘f‘or’F‘.
  2. Floating-point constants can be represented in two ways
  • In decimal notation:5.12.512.0 f ，512.(Must have decimal point)
  • Scientific notation:5.12 e2 、 5.12 e-2
  1. In general, it should be useddoubleType, because it is more thanfloatType is more accurate.
  2. printf("d1=%f ", d1);// The decimal point is kept by default when output6 位
  3. code
  • In the output, if%fThe decimal point is kept by default6Bit if you want the given number to exceedsix, you can write:d1=%7f.7It stands behind the decimal pointseven
#include<stdio.h>
void main(a){
	// Float constants are double by default. Float constants must be followed by 'f 'or 'f'.
	float d1 =1.1; // Truncate from "double "to" float",1.1 is double
	float d2 =1.1 f;/ / 1.1 f is a float
	double d3= 1.3; // ok
	
	double d4 = 5.12;
	double d5 =512.;/ / equivalent to 0.512
	
	double d6 = 5.12 e2; / / equivalent 5.12 * 10 ^ (2) = 512
	double d7 = 5.12 e-2; // Equivalent 5.12*(10^-2)=5.12/100= 0.0512
	
	printf("d1=%f d2=%f d3=%f d4=%f d5=%f d6=%f d7=%f",d1,d2,d3,d4,d5,d6,d7);
	getchar();
}
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