逻辑AND（&&）运算符，带C语言示例

Logical operators

work with the test conditions and return the result based on the condition's results, these can also be used to validate multiple conditions together.

逻辑运算符

使用测试条件并根据条件的结果返回结果，这些

逻辑运算符

还可用于一起验证多个条件。

In C programming language, there are three logical operators

Logical AND (&&)

,

Logical OR (||)

and

Logician NOT (!)

.

在C编程语言中，有三个逻辑运算符

Logical AND(&&)

，

Logical OR(||)

和

Logician NOT(！)

。

C语言中的逻辑AND(&&)运算符 (Logical AND (&&) operator in C)

Logical AND

is denoted by double ampersand characters (&&), it is used to check the combinations of more than one conditions; it is a binary operator – which requires two operands.

逻辑与

通过双符号字符(&&)，则用于检查的一个以上的条件的组合表示; 它是一个二进制运算符–需要两个操作数。

If both of the operand's values is

non-zero

(true),

Logical AND (&&) operator

returns 1 (true), else it returns 0 (false).

如果两个操作数的值都不

为零

(true)，则

逻辑AND(&&)运算符

返回1(true)，否则返回0(false)。

Syntax of Logical AND operator: 逻辑AND运算符的语法：

condition1 && condition2
           

Truth table of logical AND operator: 逻辑AND运算符的真值表：

condition1 	condition2	condition1 && condition2
1		1		1
1		0		0
0		1		0
0		0		0
           

逻辑AND(&&)运算符的C示例 (C examples of Logical AND (&&) operator )

Example 1:

Take a number and apply some of the conditions and print the result of expression containing logical AND operator.

示例1：

取一个数字并应用一些条件，并打印包含逻辑AND运算符的表达式的结果。

// C program to demonstrate example of 
// Logical AND (&&) operator 

#include <stdio.h>

int main()
{
    int num =10;
    
    //printing result with AND (&&) operator
    printf("%d\n",(num==10 && num>=5));
    printf("%d\n",(num>=5  && num<=50));
    printf("%d\n",(num!=10 && num>=5));
    printf("%d\n",(num>=20 && num<=50));
    
    return 0;
}
           

Output 输出量

1
1
0
0
           

Example 2:

Input age and check it is teenage or not.

示例2：

输入年龄并检查年龄是否未满。

// C program to demonstrate example of 
// Logical AND (&&) operator 
// Input age and check it is teenage or not.

#include <stdio.h>

int main()
{
    int age;
    
    //input age
    printf("Enter age: ");
    scanf("%d", &age);
    
    //check teenage or not
    if(age>=13 && age<=19)
        printf("%d is a teenage value\n", age);
    else
        printf("%d is not a teenage value\n", age);
    
    return 0;
}
           

Output 输出量

First run:
Enter age: 18
18 is a teenage value

Second run:
Enter age: 12
12 is not a teenage value
           

Example 3:

Input username and password and validate the values with predefined values of username and password.

示例3：

输入用户名和密码，并使用用户名和密码的预定义值验证值。

// C program to demonstrate example of 
// Logical AND (&&) operator 
// Input username and password and validate the values 
// with predefined values of username and password.

#include <stdio.h>
#include <string.h>

// define a fixed value for USERNAME and PASSWORD
#define USERNAME "admin"
#define PASSWORD "[email protected]"

int main()
{
    char un[50], pass[50];
    
    //input USERNAME and PASSWORD
    printf("Enter username: ");
    scanf("%s", un);
    printf("Enter password: ");
    scanf("%s", pass);
    
    //validate username and password
    if(strcmp(USERNAME,un)==0 && strcmp(PASSWORD, pass)==0)
        printf("Input credentials are correct\n");
    else
        printf("Input credentials are not correct\n");
    
    return 0;
}
           

Output 输出量

First run:
Enter username: admin
Enter password: [email protected]
Input credentials are correct

Second run:
Enter username: admin
Enter password: [email protected]
Input credentials are not correct
           

翻译自: https://www.includehelp.com/c/logical-and-operator-with-example-in-c.aspx