lrint函数

C ++ lrint()函数 (C++ lrint() function)

lrint() function is a library function of cmath header, it is used to round the given value and convert it to a long integer. It accepts a value (float, double, or long double) and returns a long integer value after rounding it based on the rounding direction specified by fegetround() function.

lrint()函数是cmath标头的库函数，用于舍入给定值并将其转换为长整数。 它接受一个值( float ， double或long double )，并在根据fegetround()函数指定的舍入方向将其舍入后返回一个长整数值。

Syntax of lrint() function:

lrint()函数的语法：

C++11:

C ++ 11：

long int lrint (double x);    long int lrint (float x);    long int lrint (long double x);    long int lrint (T x);

Parameter(s):

参数：

• x – represents the value to round.

  x –表示要取整的值。

Return value:

返回值：

The returns type of this function is long int, it returns a long integer value rounded to nearby integral.

此函数的返回类型为long int ，它返回一个四舍五入到附近整数的长整数值。

Example:

例：

Input:    float x = 123.4f;        Function call:    lrint(x);        Output:    123    Input:    float x = 123.5f;        Function call:    lrint(x);        Output:    124

C ++代码演示lrint()函数的示例 (C++ code to demonstrate the example of lrint() function)

// C++ code to demonstrate the example of// lrint() function#include 
    
     #include 
     
      #include 
      
        // for fegetround()using namespace std;int main(){    float x = 0.0f;    cout << "Specified rounding is: ";    switch (fegetround()) {    case FE_DOWNWARD:        cout << "Downward" << endl;        break;    case FE_TONEAREST:        cout << "To-nearest" << endl;        break;    case FE_TOWARDZERO:        cout << "Toward-zero" << endl;        break;    case FE_UPWARD:        cout << "Upward" << endl;        break;    default:        cout << "Unknown" << endl;    }    x = 123.4f;    cout << "lrint(" << x << "): " << lrint(x) << endl;    x = 123.5f;    cout << "lrint(" << x << "): " << lrint(x) << endl;    x = 123.6f;    cout << "lrint(" << x << "): " << lrint(x) << endl;    x = -123.4f;    cout << "lrint(" << x << "): " << lrint(x) << endl;    x = -123.5f;    cout << "lrint(" << x << "): " << lrint(x) << endl;    x = -123.6f;    cout << "lrint(" << x << "): " << lrint(x) << endl;    return 0;}
      
     
    

Output

输出量

Specified rounding is: To-nearestlrint(123.4): 123lrint(123.5): 124lrint(123.6): 124lrint(-123.4): -123lrint(-123.5): -124lrint(-123.6): -124

Reference:

参考：

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lrint函数