1、软考程序员章节常考知识点复习笔记第八章汇总2013年软考程序员章节常考知识点复习笔记第八章查看汇总2013年软考程序员章节常考知识点复习笔记汇总12、C操作符优先级:记忆方法:去掉一个最高的,去掉一个最低的,剩下的是一、二、三、赋值;双目运算符中,顺序为算术、关系和逻辑,移位和逻辑位插入其中。-摘自C语言程序设计实用问答问题:如何记住运算符的15种优先级和结合性?解答:C语言中运算符种类比较繁多,优先级有15种,结合性有两种。如何记忆两种结合性和15种优先级?下面讲述一种记忆方法。结合性有两种,一种是自左至右,另一种是自右至左,大部分运算符的结合性是自左至右,只有单目运算符、三目运算符的赋值运
2、算符的结合性自右至左。优先级有15种,记忆方法如下:记住一个最高的:构造类型的元素或成员以及小括号。记住一个最低的:逗号运算符。剩余的是一、二、三、赋值意思是单目、双目、三目和赋值运算符。在诸多运算符中,又分为:算术、关系、逻辑。两种位操作运算符中,移位运算符在算术运算符后边,逻辑位运算符在逻辑运算符的前面。再细分如下:算术运算符*,/,%高于,-。关系运算符中:,和Member access from a pointerptr-age 34;yes.Member access from an objectobj.age 34;noPost-incrementfor (int i 0; i 1
3、0; i) cout i;yes-Post-decrement0; i-) cout i;yesdynamic_castRuntime-checked type conversion(x);nostatic_castUnchecked type conversion(x);noreinterpret_castReinterpreting type conversionint const* p reinterpret_cast (0x1234);noconst_castCast away/Add constnessint* q const_cast(p);notypeidGet type inf
4、ormationstd:type_info const& t typeid(x);no3!Logical negationif (!done) .yesright to leftnotAlternate spelling for !Bitwise complementflags flags;yescomplAlternate spelling for Pre-incrementfor (i 0; i 10;i) cout i;yes-Pre-decrement0; -i) cout *Member pointer selectorptr-*var 24;yesleft to right.*Me
5、mber object selectorobj.*var 24;no5*Multiplicationint i 2 * 4;yesleft to right/Divisionfloat f 10.0 / 3.0;yes%Modulusint rem 4 % 3;yes6Additionint i 2 3;yesleft to right-Subtractionint i 5 - 1;yes7 Bitwise shift leftint flags 33 Bitwise shift right 1;yes8 Comparison less-thanif (i 42) .yesleft to ri
6、ghtComparison less-than-or-equal-toif (i Comparison greater-thanif (i 42) .yesComparison greater-than-or-equal-toif (i 42) .yes9Comparison equal-toif (i 42) .yesleft to righteqAlternate spelling for !Comparison not-equal-toif (i ! 42) .yesnot_eqAlternate spelling for !10&Bitwise ANDflags flags & 42;
7、yesleft to rightbitandAlternate spelling for &11Bitwise exclusive OR (XOR)flags flags 42;yesleft to rightxorAlternate spelling for 12|Bitwise inclusive (normal) ORflags flags | 42;yesleft to rightbitorAlternate spelling for |13&Logical ANDif (conditionA & conditionB) .yesleft to rightandAlternate spelling for &14|Logical ORif (conditionA | conditionB) .yesleft to rightorAlternate spelling for |15? :
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