Logické operátory provádějí logické operace s daným výrazem spojením dvou nebo více výrazů nebo podmínek. Může být použit v různých relačních a podmíněných výrazech. Tento operátor je založen na booleovských hodnotách pro logickou kontrolu podmínky, a pokud jsou podmínky pravdivé, vrátí 1. V opačném případě vrátí 0 (False). V programování C jsou logické operátory klasifikovány do tří typů, jako je logický operátor AND (&&), logický operátor OR (||) a logický operátor NOT (!). Zde se seznámíme s operátorem Logical AND a jeho různými příklady v programovacím jazyce C.
Logický operátor AND
Logický operátor AND je reprezentován jako symbol dvojitého ampersandu '&&'. Zkontroluje podmínku dvou nebo více operandů kombinací ve výrazu, a pokud jsou všechny podmínky pravdivé, logický operátor AND vrátí booleovskou hodnotu true nebo 1. V opačném případě vrátí false nebo 0.
výchozí parametry java
Poznámka: Pokud je hodnota obou nenulová, podmínka zůstane pravdivá. V opačném případě vrátí logický operátor AND (&&) 0 (nepravda).
Syntax
(condition1 && condition2)
Ve výše uvedené syntaxi jsou dvě podmínky, podmínka1 a podmínka2, a mezi nimi dvojitý ampersand (&&). Pokud jsou splněny obě podmínky, logický operátor AND vrátí booleovskou hodnotu 1 nebo true. V opačném případě vrátí hodnotu false.
Pravdivostní tabulka logického operátoru AND (&&).
| A | B | A && B |
|---|---|---|
| 1 | 1 | 1 |
| 1 | 0 | 0 |
| 0 | 1 | 0 |
| 0 | 0 | 0 |
Příklad 1: Program pro demonstraci logického operátoru AND v C
#include #include int main () { // declare variable int n = 20; // use Logical AND (&&) operator to check the condition printf (' %d
', (n == 20 && n >= 8)); // condition is true, therefore it returns 1 printf (' %d
', (n >= 1 && n >= 20)); printf (' %d
', (n == 10 && n >= 0)); printf (' %d
', (n >= 20 && n <= 40)); return 0; } < pre> <p> <strong>Output</strong> </p> <pre> 1 1 0 1 </pre> <p> <strong>Example 2: Program to find the largest number using the Logical AND operator</strong> </p> <pre> #include #include int main () { // declare integer type variable int x, y, z; printf (' Enter the first number: '); scanf ('%d', &x); printf (' Enter the second number: '); scanf ('%d', &y); printf (' Enter the third number: '); scanf ('%d', &z); // use logical AND operator to validate the condition if ( x >= y && x >= z ) { printf (' %d is the largest number of all. ', x); } else if ( y >= x && y >= z) { printf (' %d is the largest number of all. ', y); } else { printf ( ' %d is the largest number of all. ', z); } return 0; } </pre> <p> <strong>Output</strong> </p> <pre> Enter the first number: 20 Enter the second number: 10 Enter the third number: 50 50 is the largest number of all </pre> <p> <strong>Example 3: Program to use the Logical AND (&&) operator to check whether the user is teenager or not.</strong> </p> <pre> #include #include int main () { // declare variable int age; printf (' Enter the age: '); scanf (' %d', &age); // get age // use logical AND operator to check more than one condition if ( age >= 13 && age <= 19) { printf (' %d is a teenager age. ', age); } else not return 0; < pre> <p> <strong>Output</strong> </p> <pre> Enter the age: 17 17 is a teenager age. 2nd execution: Enter the age: 10 10 is not a teenager age. </pre> <p> <strong>Example 4: Program to validate whether the entered number is in the defined range or not.</strong> </p> <pre> #include int main () { int num; printf (' Enter a number between 1 to 50: '); scanf (' %d', &num); //get the number // use logical AND operator to check condition if ( (num > 0 ) && (num 50 ) && ( num <= 50 100)) { printf (' the entered number is in range and 100. '); } else please enter defined range. return 0; < pre> <p> <strong>Output</strong> </p> <pre> Enter a number between 1 to 50: 19 The entered number is in the range 0 and 50. 2nd Run Enter a number between 1 to 50: 51 The entered number is in the range 50 and 100. 3rd execution: Enter a number between 1 to 50: 0 Please enter the number is in the defined range. </pre> <p> <strong>Example 5: Program to validate the username and password entered by the user is correct or not using the predefined username and password.</strong> </p> <pre> #include #include // use #define macro to define the values for UserName and Password #define UserName 'system' #define Password 'admin@123' int main () { // declare character type array char un[50], pass[50]; // take UserName and Password from user printf ( ' Enter the username: ' ); scanf (' %s', un); printf ( ' Enter the password: ' ); scanf (' %s', pass); // use if statement and Logical AND operator to validate the condition if (strcmp (UserName, un) == 0 && strcmp (Password, pass) == 0) { printf ('
The user's credentials are correct. '); } else { printf ( '
The user's credentials are incorrect. '); } return 0; } </pre> <p> <strong>Output</strong> </p> <pre> Enter the username: system Enter the password: admin@123 The user's credentials are correct. 2nd execution Enter the username: system Enter the password: admin@1234 The user's credentials are incorrect. </pre> <hr></=></pre></=></pre></=> Příklad 2: Program pro nalezení největšího čísla pomocí logického operátoru AND
#include #include int main () { // declare integer type variable int x, y, z; printf (' Enter the first number: '); scanf ('%d', &x); printf (' Enter the second number: '); scanf ('%d', &y); printf (' Enter the third number: '); scanf ('%d', &z); // use logical AND operator to validate the condition if ( x >= y && x >= z ) { printf (' %d is the largest number of all. ', x); } else if ( y >= x && y >= z) { printf (' %d is the largest number of all. ', y); } else { printf ( ' %d is the largest number of all. ', z); } return 0; } Výstup
Enter the first number: 20 Enter the second number: 10 Enter the third number: 50 50 is the largest number of all
Příklad 3: Program pro použití operátoru Logical AND (&&) ke kontrole, zda je uživatel teenager nebo ne.
#include #include int main () { // declare variable int age; printf (' Enter the age: '); scanf (' %d', &age); // get age // use logical AND operator to check more than one condition if ( age >= 13 && age <= 19) { printf (\' %d is a teenager age. \', age); } else not return 0; < pre> <p> <strong>Output</strong> </p> <pre> Enter the age: 17 17 is a teenager age. 2nd execution: Enter the age: 10 10 is not a teenager age. </pre> <p> <strong>Example 4: Program to validate whether the entered number is in the defined range or not.</strong> </p> <pre> #include int main () { int num; printf (' Enter a number between 1 to 50: '); scanf (' %d', &num); //get the number // use logical AND operator to check condition if ( (num > 0 ) && (num 50 ) && ( num <= 50 100)) { printf (\' the entered number is in range and 100. \'); } else please enter defined range. return 0; < pre> <p> <strong>Output</strong> </p> <pre> Enter a number between 1 to 50: 19 The entered number is in the range 0 and 50. 2nd Run Enter a number between 1 to 50: 51 The entered number is in the range 50 and 100. 3rd execution: Enter a number between 1 to 50: 0 Please enter the number is in the defined range. </pre> <p> <strong>Example 5: Program to validate the username and password entered by the user is correct or not using the predefined username and password.</strong> </p> <pre> #include #include // use #define macro to define the values for UserName and Password #define UserName 'system' #define Password 'admin@123' int main () { // declare character type array char un[50], pass[50]; // take UserName and Password from user printf ( ' Enter the username: ' ); scanf (' %s', un); printf ( ' Enter the password: ' ); scanf (' %s', pass); // use if statement and Logical AND operator to validate the condition if (strcmp (UserName, un) == 0 && strcmp (Password, pass) == 0) { printf ('
The user's credentials are correct. '); } else { printf ( '
The user's credentials are incorrect. '); } return 0; } </pre> <p> <strong>Output</strong> </p> <pre> Enter the username: system Enter the password: admin@123 The user's credentials are correct. 2nd execution Enter the username: system Enter the password: admin@1234 The user's credentials are incorrect. </pre> <hr></=></pre></=> Příklad 4: Program pro ověření, zda je zadané číslo v definovaném rozsahu nebo ne.
#include int main () { int num; printf (' Enter a number between 1 to 50: '); scanf (' %d', &num); //get the number // use logical AND operator to check condition if ( (num > 0 ) && (num 50 ) && ( num <= 50 100)) { printf (\' the entered number is in range and 100. \'); } else please enter defined range. return 0; < pre> <p> <strong>Output</strong> </p> <pre> Enter a number between 1 to 50: 19 The entered number is in the range 0 and 50. 2nd Run Enter a number between 1 to 50: 51 The entered number is in the range 50 and 100. 3rd execution: Enter a number between 1 to 50: 0 Please enter the number is in the defined range. </pre> <p> <strong>Example 5: Program to validate the username and password entered by the user is correct or not using the predefined username and password.</strong> </p> <pre> #include #include // use #define macro to define the values for UserName and Password #define UserName 'system' #define Password 'admin@123' int main () { // declare character type array char un[50], pass[50]; // take UserName and Password from user printf ( ' Enter the username: ' ); scanf (' %s', un); printf ( ' Enter the password: ' ); scanf (' %s', pass); // use if statement and Logical AND operator to validate the condition if (strcmp (UserName, un) == 0 && strcmp (Password, pass) == 0) { printf ('
The user's credentials are correct. '); } else { printf ( '
The user's credentials are incorrect. '); } return 0; } </pre> <p> <strong>Output</strong> </p> <pre> Enter the username: system Enter the password: admin@123 The user's credentials are correct. 2nd execution Enter the username: system Enter the password: admin@1234 The user's credentials are incorrect. </pre> <hr></=> Příklad 5: Program pro ověření, zda je uživatelské jméno a heslo zadané uživatelem správné nebo nepoužívá předdefinované uživatelské jméno a heslo.
herec rohit Shetty
#include #include // use #define macro to define the values for UserName and Password #define UserName 'system' #define Password 'admin@123' int main () { // declare character type array char un[50], pass[50]; // take UserName and Password from user printf ( ' Enter the username: ' ); scanf (' %s', un); printf ( ' Enter the password: ' ); scanf (' %s', pass); // use if statement and Logical AND operator to validate the condition if (strcmp (UserName, un) == 0 && strcmp (Password, pass) == 0) { printf ('
The user's credentials are correct. '); } else { printf ( '
The user's credentials are incorrect. '); } return 0; } Výstup
Enter the username: system Enter the password: admin@123 The user's credentials are correct. 2nd execution Enter the username: system Enter the password: admin@1234 The user's credentials are incorrect.