Rules that govern the order in which operators are applied to operands, e. g., consider a + b + c, the expression is ambiguous unless it is understood that multiplication has precedence over addition.

• 确定操作符作用于操作数的次序的一组规则。例如,考虑a+b+c,除非明确了乘法优先于加法,否则此表达式有两义性。