Dart运算符算数运算符 - 闪电教程JSRUN

算术运算符

Dart 支持常用的运算运算符，如下表所示：

Operator	Meaning
+	Add
-	Subtract
-expr	Unary minus, also known as negation (reverse the sign of the expression)
*	Multiply
/	Divide
~/	Divide, returning an integer result
%	Get the remainder of an integer division (modulo)

示例：

assert(2 + 3 == 5);
assert(2 - 3 == -1);
assert(2 * 3 == 6);
assert(5 / 2 == 2.5); // 结果是双浮点型
assert(5 ~/ 2 == 2); // 结果是整型
assert(5 % 2 == 1); // 余数

assert('5/2 = ${5 ~/ 2} r ${5 % 2}' == '5/2 = 2 r 1');

Dart 还支持前缀和后缀，自增和自减运算符。

Operator	Meaning
++var	var = var + 1 (expression value is var + 1)
var++	var = var + 1 (expression value is var)
--var	var = var – 1 (expression value is var – 1)
var--	var = var = var – 1 (expression value is var)

示例：

var a, b;

a = 0;
b = ++a; // a自加后赋值给b。
assert(a == b); // 1 == 1

a = 0;
b = a++; // a先赋值给b后，a自加。
assert(a != b); // 1 != 0

a = 0;
b = --a; // a自减后赋值给b。
assert(a == b); // -1 == -1

a = 0;
b = a--; // a先赋值给b后，a自减。
assert(a != b); // -1 != 0

算数运算符

算术运算符

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