运算符优先级决定的条款在表达式中的分组。这会影响一个表达式如何计算。某些运算符的优先级高于其他例如，乘法运算符的优先级比加法运算符高。
例如X =7 +3* 2 这里，x被赋值13，而不是20，因为运算符*的优先级高于+，所以它首先被乘以3 * 2，然后再加上7。
这里，具有最高优先级的操作出现在表的顶部，那些具有最低出现在底部。在表达式中，优先级较高的运算符将首先计算。
| 分类%uA0 | Operator%uA0 | 关联%uA0 |
|---|---|---|
| Postfix%uA0 | () [] -> . ++ - - %uA0 | Left to right%uA0 |
| Unary%uA0 | + - ! ~ ++ - - (type)* & sizeof%uA0 | Right to left%uA0 |
| Multiplicative %uA0 | * / %%uA0 | Left to right%uA0 |
| Additive %uA0 | + -%uA0 | Left to right%uA0 |
| Shift %uA0 | << >>%uA0 | Left to right%uA0 |
| Relational %uA0 | < <= > >=%uA0 | Left to right%uA0 |
| Equality %uA0 | == !=%uA0 | Left to right%uA0 |
| Bitwise AND%uA0 | &%uA0 | Left to right%uA0 |
| Bitwise XOR%uA0 | ^%uA0 | Left to right%uA0 |
| Bitwise OR%uA0 | |%uA0 | Left to right%uA0 |
| Logical AND%uA0 | &&%uA0 | Left to right%uA0 |
| Logical OR%uA0 | ||%uA0 | Left to right%uA0 |
| Conditional%uA0 | ?:%uA0 | Right to left%uA0 |
| Assignment%uA0 | = += -= *= /= %=>>= <<= &= ^= |=%uA0 | Right to left%uA0 |
| Comma%uA0 | ,%uA0 | Left to right%uA0 |
例子
试试下面的例子就明白了在D编程语言中的运算符优先级可供选择：
import std.stdio int main(string[] args) { int a = 20 int b = 10 int c = 15 int d = 5 int e e = (a + b) * c / d // ( 30 * 15 ) / 5 writefln("Value of (a + b) * c / d is : %d ", e ) e = ((a + b) * c) / d // (30 * 15 ) / 5 writefln("Value of ((a + b) * c) / d is : %d " , e ) e = (a + b) * (c / d) // (30) * (15/5) writefln("Value of (a + b) * (c / d) is : %d ", e ) e = a + (b * c) / d // 20 + (150/5) writefln("Value of a + (b * c) / d is : %d " , e ) return 0 }
当编译并执行上面的程序它会产生以下结果：
Value of (a + b) * c / d is : 90 Value of ((a + b) * c) / d is : 90 Value of (a + b) * (c / d) is : 90 Value of a + (b * c) / d is : 50