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Opérateur logique NOT (!) en C

Cette section abordera l'opérateur logique NON (!) dans le langage de programmation C. Comme nous le savons déjà, l'opérateur logique est utilisé pour effectuer l'opération logique en combinant deux ou plusieurs conditions sur les expressions données. Si les conditions logiques des opérandes sont vraies, l'opérateur renvoie de vraies valeurs booléennes ou 1. Sinon, il renvoie une fausse valeur booléenne ou 0. Les opérateurs logiques sont classés en trois parties : Opérateurs ET logique, OU logique et NON logique.

Opérateur logique NOT (!) en C

Le opérateur ET logique est utilisé pour vérifier que les conditions de deux ou plusieurs opérandes restants sont vraies dans une expression donnée ; l'opérateur AND renvoie une valeur vraie ou non nulle (1). Sinon, il renvoie une valeur fausse ou 0. Ainsi, nous pouvons dire que l'opérateur logique ET ne peut fonctionner que dans une expression lorsque les conditions des deux opérandes sont vraies, et si une condition n'est pas vraie, il renvoie 0. L'opérateur logique ET est représenté par le symbole double esperluette '&&'.

chaîne.format en java

Syntaxe:

 (A > b && b > c) 

Le opérateur logique OU est utilisé pour vérifier les conditions des deux opérandes (A et B), et si l'un des opérandes ou expressions est vrai, l'opérateur renvoie une vraie valeur booléenne. De même, si aucune des expressions n’est vraie, elle renvoie une valeur fausse ou nulle. L'opérateur logique OU est désigné par le double tube '||' symbole.

Syntaxe:

 (A &gt; B) || (A <c) < pre> <h3>Logical NOT operator</h3> <p>The logical NOT operator is represented as the &apos;!&apos; symbol, which is used to reverse the result of any given expression or condition. If the result of an expression is non-zero or true, the result will be reversed as zero or false value. Similarly, if the condition&apos;s result is false or 0, the NOT operator reverses the result and returns 1 or true.</p> <p>For example, suppose the user enters a non-zero value is 5, the logical NOT (!) operator returns the 0 or false Boolean value. And if the user enters a zero (0) value, the operator returns the true Boolean value or 1. </p> <p> <strong>Syntax of the logical NOT operator</strong> </p> <pre> ! (condition); // It &apos;!&apos; represents the NOT operator </pre> <p>Here, the &apos;!&apos; symbol represents the logical NOT operator, which inverses the result of the given condition.</p> <h3>The truth table of the logical NOT operator:</h3> <p>Following is the truth table of the logical not operator in C</p> <pre> condition !(condition) 1 0 0 1 </pre> <h3>Example 1: Program to use the logical NOT operator in C</h3> <p>Let&apos;s create a simple program to reverse the given condition of the operands in the C programming language.</p> <pre> /* demonstration the use of the logical not operator in C. */ #include #include int main () { // declare an initialize x variable int x = 5; // display the result generated using the NOT (!) operator printf (&apos; The return value = %d 
&apos;, ! (x == 5)); printf (&apos; The return value = %d 
&apos;, ! (x != 5)); printf (&apos; The return value = %d 
&apos;, ! (x &gt;= 3)); printf (&apos; The return value = %d 
&apos;, ! (x <3)); return 0; } < pre> <p> <strong>Output:</strong> </p> <pre> The return value = 0 The return value = 1 The return value = 0 The return value = 1 </pre> <p>In the above program, we use the NOT (!) operator to reverse the result of the various expression, such as the condition of the variable x is equal to 5, which is true. Still, the NOT operator reverses the result and returns 0. Similarly, we defined the condition (x!=5), but the logical operator changed its result and returned 1 and so on.</p> <h3>Example 2: Program to input a number to perform the logical NOT operator</h3> <p>Let&apos;s create a simple program to get the reverse result of an integer number using the logical NOT (!) operator in the C programming language.</p> <pre> /* demonstration the use of the logical not operator in C. */ #include #include int main () { // declare an initialize x variable int x, n; printf (&apos; Enter the number: &apos;); scanf (&apos;%d&apos;, &amp;x); n = !x; // use logical not operator to reverse the condition printf (&apos; The result of x: %d&apos;, n); // display the result return 0; } </pre> <p> <strong>Output:</strong> </p> <pre> Enter the number: 7 The result of x: 0 </pre> <p>In the above program, we input an integer number 7 from the user and store it into x variable. After that, the logical NOT (!) operator reverses the value of x (non-zero) and returns zero (0) to print the result of x.</p> <p> <strong>2<sup>nd</sup> execution:</strong> </p> <pre> Enter the number: 0 The result of x: 1 </pre> <p>Similarly, we input zero (0) from the user and use the logical NOT (!) operator to reverse the value of x to a non-zero value, which is 1.</p> <h3>Example 3: Program to find the leap year using the logical AND (&amp;&amp;), OR (||), and NOT (!) operator</h3> <p>Let&apos;s write a simple program to check whether the given year is a leap or not using the logical AND (&amp;&amp;), logical OR (||), and the logical NOT (!) operator in the C language.</p> <pre> #include #include int main () { int yr; // declare int type variable printf (&apos; Enter the year: &apos;); scanf (&apos;%d&apos;, &amp;yr); // use the if..else statement to check the condition /* &apos;&amp;&amp;&apos; (AND) operator to validate both operand, &apos;||&apos; (OR) operator check ny given expressions are true, &apos;!&apos; (NOT) check the result of (yr % 100 != 0). */ if ( (yr % 400 == 0) || (yr % 4 == 0 &amp;&amp; yr % 100 != 0)) { printf (&apos; %d is a leap year. 
&apos;, yr); } else { printf (&apos; %d is not a leap year. 
&apos;, yr); } return 0; } </pre> <p> <strong>Output:</strong> </p> <pre> Enter the year: 2020 2020 is a leap year. </pre> <p>In the above program, we enter 2020 and then check the given year by defining the if...else statement. In this statement, we defined two conditions;</p> <ol class="points"> <li>The given year is divided by 400, which is equal to 0. And then, we use the logical OR operator to check whether the left or right operand condition is true.</li> <li>In the second condition, the given year is divided by 4 and 100. But when we divide 2020 with 4, which is equal to 0. Similarly, we divide the year 2020 by 100, which is also not equal to 0. So, both the conditions are true that display the &apos;2020 is a leap year&apos;.</li> <li>But when we enter the year 2021, it prints the given result &apos;2021 is not a leap year&apos;.</li> </ol> <p> <strong>2<sup>nd</sup> execution:</strong> </p> <pre> Enter the year: 2021 2021 is not a leap year. </pre> <p> <strong>Example 4: Program to check different conditions using the AND, OR, and the NOT logical operator</strong> </p> <p>Let&apos;s write a program to demonstrate the multiple conditions of the given operands using the AND, OR, and the NOT logical operator in C.</p> <pre> /* program to check the various condition using the logical NOT operator in c. */ #include #include int main () { // declare and initialize variables int a = 20, b = 15; int n1 = 15, n2 = 17; // use logical &apos;AND&apos; and logical &apos;NOT&apos; operator if (a &gt; b &amp;&amp; a != 0) { printf (&apos; The AND (&amp;&amp;) operator said: Both conditions are true. 
 &apos;); } // use logical &apos;OR&apos; and logical &apos;NOT&apos; operator if (n1 &gt; n2 || n2 != 15) if ( ! (a &gt; b &amp;&amp; a != 0 )) { printf (&apos; The NOT (!) operator: Here both conditions are true. 
 &apos;); } else { printf (&apos; The NOT (!) operator: Here, both conditions are true. &apos; &apos; But, the status of the condition is reversed as false. 
&apos;); } return 0; } </pre> <p> <strong>Output:</strong> </p> <pre> The AND (&amp;&amp;) operator is said: Both conditions are true. The OR (||) operator is said: Only one condition is true. The NOT (!) operator: Here, both conditions are true. But, the status of the condition is reversed as false. </pre> <hr></3));></pre></c)>

Ici le '!' Le symbole représente l'opérateur logique NON, qui inverse le résultat de la condition donnée.

La table de vérité de l'opérateur logique NOT :

Voici la table de vérité de l'opérateur logique not en C

 condition !(condition) 1 0 0 1 

Exemple 1 : Programme pour utiliser l'opérateur logique NOT en C

Créons un programme simple pour inverser la condition donnée des opérandes dans le langage de programmation C.

 /* demonstration the use of the logical not operator in C. */ #include #include int main () { // declare an initialize x variable int x = 5; // display the result generated using the NOT (!) operator printf (&apos; The return value = %d 
&apos;, ! (x == 5)); printf (&apos; The return value = %d 
&apos;, ! (x != 5)); printf (&apos; The return value = %d 
&apos;, ! (x &gt;= 3)); printf (&apos; The return value = %d 
&apos;, ! (x <3)); return 0; } < pre> <p> <strong>Output:</strong> </p> <pre> The return value = 0 The return value = 1 The return value = 0 The return value = 1 </pre> <p>In the above program, we use the NOT (!) operator to reverse the result of the various expression, such as the condition of the variable x is equal to 5, which is true. Still, the NOT operator reverses the result and returns 0. Similarly, we defined the condition (x!=5), but the logical operator changed its result and returned 1 and so on.</p> <h3>Example 2: Program to input a number to perform the logical NOT operator</h3> <p>Let&apos;s create a simple program to get the reverse result of an integer number using the logical NOT (!) operator in the C programming language.</p> <pre> /* demonstration the use of the logical not operator in C. */ #include #include int main () { // declare an initialize x variable int x, n; printf (&apos; Enter the number: &apos;); scanf (&apos;%d&apos;, &amp;x); n = !x; // use logical not operator to reverse the condition printf (&apos; The result of x: %d&apos;, n); // display the result return 0; } </pre> <p> <strong>Output:</strong> </p> <pre> Enter the number: 7 The result of x: 0 </pre> <p>In the above program, we input an integer number 7 from the user and store it into x variable. After that, the logical NOT (!) operator reverses the value of x (non-zero) and returns zero (0) to print the result of x.</p> <p> <strong>2<sup>nd</sup> execution:</strong> </p> <pre> Enter the number: 0 The result of x: 1 </pre> <p>Similarly, we input zero (0) from the user and use the logical NOT (!) operator to reverse the value of x to a non-zero value, which is 1.</p> <h3>Example 3: Program to find the leap year using the logical AND (&amp;&amp;), OR (||), and NOT (!) operator</h3> <p>Let&apos;s write a simple program to check whether the given year is a leap or not using the logical AND (&amp;&amp;), logical OR (||), and the logical NOT (!) operator in the C language.</p> <pre> #include #include int main () { int yr; // declare int type variable printf (&apos; Enter the year: &apos;); scanf (&apos;%d&apos;, &amp;yr); // use the if..else statement to check the condition /* &apos;&amp;&amp;&apos; (AND) operator to validate both operand, &apos;||&apos; (OR) operator check ny given expressions are true, &apos;!&apos; (NOT) check the result of (yr % 100 != 0). */ if ( (yr % 400 == 0) || (yr % 4 == 0 &amp;&amp; yr % 100 != 0)) { printf (&apos; %d is a leap year. 
&apos;, yr); } else { printf (&apos; %d is not a leap year. 
&apos;, yr); } return 0; } </pre> <p> <strong>Output:</strong> </p> <pre> Enter the year: 2020 2020 is a leap year. </pre> <p>In the above program, we enter 2020 and then check the given year by defining the if...else statement. In this statement, we defined two conditions;</p> <ol class="points"> <li>The given year is divided by 400, which is equal to 0. And then, we use the logical OR operator to check whether the left or right operand condition is true.</li> <li>In the second condition, the given year is divided by 4 and 100. But when we divide 2020 with 4, which is equal to 0. Similarly, we divide the year 2020 by 100, which is also not equal to 0. So, both the conditions are true that display the &apos;2020 is a leap year&apos;.</li> <li>But when we enter the year 2021, it prints the given result &apos;2021 is not a leap year&apos;.</li> </ol> <p> <strong>2<sup>nd</sup> execution:</strong> </p> <pre> Enter the year: 2021 2021 is not a leap year. </pre> <p> <strong>Example 4: Program to check different conditions using the AND, OR, and the NOT logical operator</strong> </p> <p>Let&apos;s write a program to demonstrate the multiple conditions of the given operands using the AND, OR, and the NOT logical operator in C.</p> <pre> /* program to check the various condition using the logical NOT operator in c. */ #include #include int main () { // declare and initialize variables int a = 20, b = 15; int n1 = 15, n2 = 17; // use logical &apos;AND&apos; and logical &apos;NOT&apos; operator if (a &gt; b &amp;&amp; a != 0) { printf (&apos; The AND (&amp;&amp;) operator said: Both conditions are true. 
 &apos;); } // use logical &apos;OR&apos; and logical &apos;NOT&apos; operator if (n1 &gt; n2 || n2 != 15) if ( ! (a &gt; b &amp;&amp; a != 0 )) { printf (&apos; The NOT (!) operator: Here both conditions are true. 
 &apos;); } else { printf (&apos; The NOT (!) operator: Here, both conditions are true. &apos; &apos; But, the status of the condition is reversed as false. 
&apos;); } return 0; } </pre> <p> <strong>Output:</strong> </p> <pre> The AND (&amp;&amp;) operator is said: Both conditions are true. The OR (||) operator is said: Only one condition is true. The NOT (!) operator: Here, both conditions are true. But, the status of the condition is reversed as false. </pre> <hr></3));>

Dans le programme ci-dessus, nous utilisons l'opérateur NOT (!) pour inverser le résultat des différentes expressions, par exemple la condition de la variable x est égale à 5, ce qui est vrai. Pourtant, l'opérateur NOT inverse le résultat et renvoie 0. De même, nous avons défini la condition (x!=5), mais l'opérateur logique a modifié son résultat et a renvoyé 1 et ainsi de suite.

Exemple 2 : Programme pour saisir un nombre pour exécuter l'opérateur logique NON

Créons un programme simple pour obtenir le résultat inverse d'un nombre entier en utilisant l'opérateur logique NON (!) dans le langage de programmation C.

 /* demonstration the use of the logical not operator in C. */ #include #include int main () { // declare an initialize x variable int x, n; printf (&apos; Enter the number: &apos;); scanf (&apos;%d&apos;, &amp;x); n = !x; // use logical not operator to reverse the condition printf (&apos; The result of x: %d&apos;, n); // display the result return 0; } 

Sortir:

 Enter the number: 7 The result of x: 0 

Dans le programme ci-dessus, nous saisissons un nombre entier 7 provenant de l'utilisateur et le stockons dans la variable x. Après cela, l'opérateur logique NOT (!) inverse la valeur de x (différente de zéro) et renvoie zéro (0) pour imprimer le résultat de x.

2sdexécution:

 Enter the number: 0 The result of x: 1 

De même, nous saisissons zéro (0) de la part de l'utilisateur et utilisons l'opérateur logique NOT (!) pour inverser la valeur de x en une valeur non nulle, qui est 1.

Exemple 3 : programme pour trouver l'année bissextile à l'aide de l'opérateur logique AND (&&), OR (||) et NOT (!)

Écrivons un programme simple pour vérifier si l'année donnée est bissextile ou non en utilisant l'opérateur logique ET (&&), OU logique (||) et l'opérateur logique NON (!) dans le langage C.

 #include #include int main () { int yr; // declare int type variable printf (&apos; Enter the year: &apos;); scanf (&apos;%d&apos;, &amp;yr); // use the if..else statement to check the condition /* &apos;&amp;&amp;&apos; (AND) operator to validate both operand, &apos;||&apos; (OR) operator check ny given expressions are true, &apos;!&apos; (NOT) check the result of (yr % 100 != 0). */ if ( (yr % 400 == 0) || (yr % 4 == 0 &amp;&amp; yr % 100 != 0)) { printf (&apos; %d is a leap year. 
&apos;, yr); } else { printf (&apos; %d is not a leap year. 
&apos;, yr); } return 0; } 

Sortir:

alphabet numéroté
 Enter the year: 2020 2020 is a leap year. 

Dans le programme ci-dessus, nous entrons 2020 puis vérifions l'année donnée en définissant l'instruction if...else. Dans cette déclaration, nous avons défini deux conditions :

  1. L'année donnée est divisée par 400, ce qui est égal à 0. Ensuite, nous utilisons l'opérateur logique OU pour vérifier si la condition de l'opérande gauche ou droit est vraie.
  2. Dans la deuxième condition, l’année donnée est divisée par 4 et 100. Mais lorsque nous divisons 2020 par 4, ce qui est égal à 0. De même, nous divisons l’année 2020 par 100, qui n’est pas non plus égal à 0. Ainsi, les deux les conditions sont vraies pour afficher « 2020 est une année bissextile ».
  3. Mais lorsque nous entrons dans l'année 2021, le résultat affiché est '2021 n'est pas une année bissextile'.

2sdexécution:

 Enter the year: 2021 2021 is not a leap year. 

Exemple 4 : Programme pour vérifier différentes conditions à l'aide des opérateurs logiques AND, OR et NOT

Écrivons un programme pour démontrer les multiples conditions des opérandes donnés en utilisant les opérateurs logiques AND, OR et NOT en C.

 /* program to check the various condition using the logical NOT operator in c. */ #include #include int main () { // declare and initialize variables int a = 20, b = 15; int n1 = 15, n2 = 17; // use logical &apos;AND&apos; and logical &apos;NOT&apos; operator if (a &gt; b &amp;&amp; a != 0) { printf (&apos; The AND (&amp;&amp;) operator said: Both conditions are true. 
 &apos;); } // use logical &apos;OR&apos; and logical &apos;NOT&apos; operator if (n1 &gt; n2 || n2 != 15) if ( ! (a &gt; b &amp;&amp; a != 0 )) { printf (&apos; The NOT (!) operator: Here both conditions are true. 
 &apos;); } else { printf (&apos; The NOT (!) operator: Here, both conditions are true. &apos; &apos; But, the status of the condition is reversed as false. 
&apos;); } return 0; } 

Sortir:

 The AND (&amp;&amp;) operator is said: Both conditions are true. The OR (||) operator is said: Only one condition is true. The NOT (!) operator: Here, both conditions are true. But, the status of the condition is reversed as false.