LINQ |量词运算符|全部
原文:https://www.geeksforgeeks.org/linq-quantifier-operator-all/
在 LINQ，量词运算符用于返回一个布尔值，该值表明某些或所有元素是否满足给定条件。标准查询运算符支持 3 种不同类型的量词运算符:
- 全部
- 任意
- 包含
所有操作员
All 运算符用于检查序列中的每个元素，如果所有元素都满足给定的条件，那么它将返回 true。否则，返回 false。例如，我们有一个序列，即 aa，aa，aa，aa 。为了检查序列的所有元素是否都是“ aa ”我们使用了 all 运算符，该运算符检查给定序列中存在的每个元素，并返回 true，因为给定序列中存在的所有元素都满足给定条件。
要点:
- 它不支持 C# 和 VB.Net 语言中的查询语法。
- 它支持 C# 和 VB.Net 语言中方法语法。
- 它同时存在于可查询和可枚举类中。
- 如果给定的源或给定的条件为空，它将抛出 ArgumentNullException 。
- 它不返回值，而是返回真或假。
- 该操作员的返回类型为系统。布尔。
例 1:
// C# program to illustrate the
// use of All operator
using System;
using System.Linq;
using System.Collections.Generic;
class GFG {
static public void Main()
{
// Data source
int[] sequence1 = {112, 44, 55, 66,
77, 777, 56};
string[] sequence2 = {"aa", "aa", "aa",
"aa", "aa", "aa"};
// Check the sequence1 contain
// all element as 77
// Using All operator
var result1 = sequence1.All(seq => seq == 77);
Console.WriteLine("Is the given sequence contain"+
" all element as 77 : {0}", result1);
// Check the sequence2 contain
// all element as aa
// Using All operator
var result2 = sequence2.All(seq => seq == "aa");
Console.WriteLine("Is the given sequence contain"+
" all element as 'aa' : {0}", result2);
}
}
Output:
Is the given sequence contain all element as 77 : False
Is the given sequence contain all element as 'aa' : True
例 2:
// C# program to check in the employee present
// in the company are all female employee
using System;
using System.Linq;
using System.Collections.Generic;
// Employee details
public class Employee {
public int emp_id
{
get;
set;
}
public string emp_name
{
get;
set;
}
public string emp_gender
{
get;
set;
}
public string emp_hire_date
{
get;
set;
}
public int emp_salary
{
get;
set;
}
}
class GFG {
// Main method
static public void Main()
{
List<Employee> emp = new List<Employee>() {
new Employee() {emp_id = 209, emp_name = "Anjita", emp_gender = "Female",
emp_hire_date = "12/3/2017", emp_salary = 20000},
new Employee() {emp_id = 210, emp_name = "Soniya", emp_gender = "Female",
emp_hire_date = "22/4/2018", emp_salary = 30000},
new Employee() {emp_id = 211, emp_name = "Rohit", emp_gender = "Male",
emp_hire_date = "3/5/2016", emp_salary = 40000},
new Employee() {emp_id = 212, emp_name = "Supriya", emp_gender = "Female",
emp_hire_date = "4/8/2017", emp_salary = 40000},
new Employee() {emp_id = 213, emp_name = "Anil", emp_gender = "Male",
emp_hire_date = "12/1/2016", emp_salary = 40000},
new Employee() {emp_id = 214, emp_name = "Anju", emp_gender = "Female",
emp_hire_date = "17/6/2015", emp_salary = 50000},
};
// Query to check in the employee present
// in the company are all female employee
// Using All method
var res = emp.All(e => e.emp_gender == "Female");
Console.WriteLine("Is all the employees are female?: {0}", res);
}
}
Output:
Is all the employees are female?: False
版权属于：月萌API www.moonapi.com，转载请注明出处
