邏輯AND（&&）運算符，帶C語言示例

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.

邏輯運算符

使用測試條件并根據條件的結果傳回結果，這些

邏輯運算符

還可用于一起驗證多個條件。

In C programming language, there are three logical operators

Logical AND (&&)

,

Logical OR (||)

and

Logician NOT (!)

.

在C程式設計語言中，有三個邏輯運算符

Logical AND(&&)

，

Logical OR(||)

和

Logician NOT(！)

。

C語言中的邏輯AND(&&)運算符 (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.

邏輯與

通過雙符号字元(&&)，則用于檢查的一個以上的條件的組合表示; 它是一個二進制運算符–需要兩個操作數。

If both of the operand's values is

non-zero

(true),

Logical AND (&&) operator

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

如果兩個操作數的值都不

為零

(true)，則

邏輯AND(&&)運算符

傳回1(true)，否則傳回0(false)。

Syntax of Logical AND operator: 邏輯AND運算符的文法：

condition1 && condition2
           

Truth table of logical AND operator: 邏輯AND運算符的真值表：

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

邏輯AND(&&)運算符的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：

取一個數字并應用一些條件，并列印包含邏輯AND運算符的表達式的結果。

// 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 輸出量

1
1
0
0
           

Example 2:

Input age and check it is teenage or not.

示例2：

輸入年齡并檢查年齡是否未滿。

// 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 輸出量

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：

輸入使用者名和密碼，并使用使用者名和密碼的預定義值驗證值。

// 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 輸出量

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
           

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