90 lines
3.2 KiB
Plaintext
90 lines
3.2 KiB
Plaintext
\b;Les expressions
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Les expressions peuvent contenir les opérations suivantes:
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\c;+ \n; addition
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\c;- \n; soustraction
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\c;* \n; multiplication
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\c;/ \n; division
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\c;% \n; reste de la division (seulement pour le type \c;\l;int\u cbot\int;\n;)
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L'addition permet non seulement d'additionner des nombres, mais également d'appondre des \l;chaînes de caractères\u cbot\string;.
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\c;
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\s; int i = 12+3; // donne 15
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\s; string s = "a"+"bc"; // donne "abc"
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\s; int i = 2-5; // donne -3
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\s; float f = 3.01*10; // donne 30.1
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\s; int i = 5/3; // donne 1
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\s; float f = 5/3; // donne 1.67
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\s; float f = 5/0; // donne une erreur
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\s; int i = 13%5; // donne 3
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\s; int i = -8%3; // donne -2
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\n;
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Une expression peut contenir des constantes ou des \l;variables\u cbot\var;. Par exemple:
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\s;\c; 12+distance\n;
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Les multiplications et les divisions sont effectuées avant les additions et les soustractions. En cas de doute, mieux vaut utiliser des parenthèses.
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\c;
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\s; 12*a+b/c \n;est équivalent à\c; (12*a)+(b/c)
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\s; 2.5*(distance+marge)
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\n;
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Vous pouvez mettre autant d'espaces que vous le désirez, pour améliorer la lisibilité:
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\c;
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\s; 12*a + b/c
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\s; 2.5 * (distance+marge)
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\n;
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Les fonctions mathématiques suivantes sont disponibles:
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\c;sin(angle) \n;sinus
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\c;cos(angle) \n;cosinus
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\c;tan(angle) \n;tangente
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\c;asin(valeur) \n;arc-sinus
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\c;acos(valeur) \n;arc-cosinus
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\c;atan(valeur) \n;arc-tangente
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\c;sqrt(valeur) \n;racine carrée
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\c;pow(x, y) \n;x puissance y
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\c;rand() \n;valeur aléatoire comprise entre 0 et 1
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\c;abs(valeur) \n;valeur absolue
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Les angles sont exprimés en degrés.
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\t;Compound assignment operators (for specialists)
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Besides the \c;=\n; operators for variable assignment there are several compound-assignment operators.
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The compound-assignment operators combine the \c;=\n; assignment operator with another binary operator such as \c;+\n; or \c;-\n;. Compound-assignment operators perform the operation specified by the additional operator and then assign the result to the left operand. For example, a compound-assignment expression such as
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\c;\s;expression1 += expression2
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is equivalent to
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\c;\s;expression1 = expression1 + expression2
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\c;+=\n; addition
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\c;-=\n; subtraction
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\c;*=\n; multiplication
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\c;/=\n; division
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\c;%=\n; remainder of the division (only for the type \c;\l;int\u cbot\int;\n;)
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\t;Prefix and posfix increment- and decrement operators (for specialists)
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The operators \c;++\n; and \c;--\n; allow you to increment (++) or to decrement (--) a variable in very compact and efficient manner.
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For example to increment the variable \c;a\n; you can write
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\c;\s; a++ ;
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\n;instead of
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\c;\s; a = a + 1 ;
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\n;
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The value of the expression \c;a++\n; is the value of the variable \c;a\n; before the increment. If you use the prefix operator \c;++a\n; the value of the expression is the value of the variable \c;a\n; after the increment. The same holds for the \c;--\n; decrement operator.
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Exemples:
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\c;\s; a = 2 ;
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\s; b = a++ ;
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\s; // now b contains 2 and a contains 3
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\c;\s; a = 2 ;
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\s; b = ++a ;
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\s; // now b contains 3 and a contains 3
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\n;
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\t;Voir aussi
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\l;Programmation\u cbot;, \l;types\u cbot\type; et \l;catégories\u cbot\category;.
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