ios开发---浮点数据的四舍五入、进一、退位 方法

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1、四舍五入：要保留的小数点位后面的以为如>=5，则向前进1，反之，舍去

//1️⃣

float testNumber1 = 4.83;

int result = （int）roundf(testNumber);

NSLog(@"roundf(%0.2f) = %d",testNumber,result);

//输出roundf(4.83) = 5;

//2️⃣

float testNumber1 = 4.23;

int result = （int）roundf(testNumber);

NSLog(@"roundf(%0.2f) = %d",testNumber,result);

//输出roundf(4.23) = 4;

```

```

2.进一：要保留的小数位后面一位无论为多少，都向前进1

//1️⃣

float testNumber1 = 4.83;

int result = （int）ceilf(testNumber);

NSLog(@"roundf(%0.2f) = %d",testNumber,result);

//输出roundf(4.83) = 5;

//2️⃣

float testNumber1 = 4.23;

int result = （int）ceilf(testNumber);

NSLog(@"ceilf(%0.2f) = %d",testNumber,result);

//输出rceilf(4.23) = 5;

```

```

3.退位：要保留的小数位后面一位无论为多少，都舍去

//1️⃣

float testNumber1 = 4.83;

int result = （int）floorf(testNumber);

NSLog(@"floorf(%0.2f) = %d",testNumber,result);

//输出floorf(4.83) = 4;

//2️⃣

float testNumber1 = 4.23;

int result = （int）floorf(testNumber);

NSLog(@"floorf(%0.2f) = %d",testNumber,result);

//输出floorf(4.23) = 5;

```