Objective-c floating point conversion integer (rounding up, rounding down)

Objective-c expands C, and naturally many usages are consistent with C. For example, the floating-point number is converted into integers, there are four cases.
1. Simple and rough, direct conversion

float f = 1.5; int a; a = (int)f; NSLog("a = %d",a);

The output result is 1. (int) is a forced type conversion that discards the decimal part of a floating-point number.

2. Gaussian function, rounding down

1.6; int a; a = floor(f); NSLog("a = %d",a);

The output result is 1. The floor () method is rounded down, similar to the Gaussian function in mathematics []. Gets the largest integer that is not larger than the floating-point number, which is the part of the floating-point number for a positive number and minus 1 for the complex number after the floating-point part is discarded.

3.ceil function, rounding up.

1.5; int a; a = ceil(f); NSLog("a = %d",a);

The output result is 2. The Ceil () method is rounded up to get the smallest integer not less than the floating-point number, and for positive numbers it discards the floating-point number and adds 1, which is the part of the floating-point number that is discarded for the plural.

4. Rounding by forcing type conversion.

float f = 1.5; int a; a = (int)(f+0.5); NSLog("a = %d",a);

Objective-c floating point conversion integer (rounding up, rounding down)