clean code meaningful names

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 1 Meaningful Names:
 2 
 3 
 4 use Intention-Revealing Names //nice,Everyone who  reads your code (including you) will be happier if you do.
 5 
 6     The name of a variable, function, or class, should answer all the big questions. It
 7     should tell you why it exists, what it does, and how it is used. If a name requires a com-
 8     ment, then the name does not reveal its intent.//Good Name can help us .
 9 
10     Choosing names that reveal intent can make it much easier to understand and change code 
11 
12 Avoid Disinformation 
13 
14     Programmers must avoid leaving false clues that obscure the meaning of code.We should avoid 
words whose entrenched meanings vary from our intended meaning. 15 16 Do not refer to a grouping of accounts as an accountList unless it’s actually a List. 17 The word list means something specific to programmers. If the container holding the 18 accounts is not actually a List, it may lead to false conclusions.1 So accountGroup or 19 bunchOfAccounts or just plain accounts would be better. 20 21 Make Meaningful Distinctions 22 23 It is not sufficient to add number series or noise words, even though the compiler is 24 satisfied. If names must be different, then they should also mean something different. 25 26 In the absence of specific conventions, the variable moneyAmount is indistinguishable 27 from money, customerInfo is indistinguishable from customer, accountData is indistinguish- 28 able from account, and theMessage is indistinguishable from message. Distinguish names in 29 such a way that the reader knows what the differences offer. 30 31 Use Pronounceable Names 32 33 Humans are good at words. A significant part of our brains is dedicated to the concept of 34 words. And words are, by definition, pronounceable. 35 36 In the absence of specific conventions, the variable moneyAmount is indistinguishable 37 from money, customerInfo is indistinguishable from customer, accountData is indistinguishable 38 from account, and theMessage is indistinguishable from message. Distinguish names in 39 such a way that the reader knows what the differences offer. 40 41 If you can’t pronounce it, you can’t discuss it without sounding like an idiot. 42 43 44 Use Searchable Names 45 46 Single-letter names and numeric constants have a particular problem in that they are not 47 easy to locate across a body of text. 48 49 My personal preference is that single-letter names can ONLY be used as local vari- 50 ables inside short methods

我在项目中大部分都是用的pronounceable names,因为关联的表越来多,涉及到东西也会比较多,名字---见名知意,不仅可以快速的理解代表的含义,也可以知道code的含义或着其目的。
Avoid Encodings

    We have enough encodings to deal with without adding more to our burden. Encoding
    type or scope information into names simply adds an extra burden of deciphering

    Encoded namesare seldom pronounceable and are easy to mis-type.

Hungarian Notation

        So nowadays HN and other forms of type encoding are simply impediments.
    They make it harder to change the name or type of a variable, function, or class. They
    make it harder to read the code. And they create the possibility that the encoding system
    will mislead the reader.

Member Prefixes
        You also don’t need to prefix member variables with m_ anymore. Your classes and func-
    tions should be small enough that you don’t need them. And you should be using an edit-
    ing environment that highlights or colorizes members to make them distinct.

        Besides, people quickly learn to ignore the prefix (or suffix) to see the meaningful
    part of the name. The more we read the code, the less we see the prefixes. Eventually the
    prefixes become unseen clutter and a marker of older code.


Interfaces and Implementations
    These are sometimes a special case for encodings.
    For example, say you are building an ABSTRACT FACTORY for the creation of shapes.
    what should you name them?
        I just want them to know that it’s a ShapeFactory. 
        So if I must encode either the interface or the implementation, I choose
    the implementation. Calling it ShapeFactoryImp, or even the hideous CShapeFactory, 
    is preferable to encoding the interface.


Avoid Mental Mapping

        Readers shouldn’t have to mentally translate your names into other names they already
    know. This problem generally arises from a choice to use neither problem domain terms
    nor solution domain terms.

        This is a problem with single-letter variable names.

        in most other contexts a single-letter name is a poor choice; it’s just a place
    holder that the reader must mentally map to the actual concept. There can be no worse rea-
    son for using the name c than because a and b were already taken.


        One difference between a smart programmer and a professional programmer is that
    the professional understands that clarity is king. Professionals use their powers for good
    and write code that others can understand

Class Names
    
    A class name should not be a verb.

Method Names
        Methods should have verb or verb phrase names like postPayment, deletePage, or save.
    Accessors, mutators, and predicates should be named for their value and prefixed with get,
    set, and is according to the javabean standard.4
    
    For example,
        Complex fulcrumPoint = Complex.FromRealNumber(23.0);
    is generally better than
        Complex fulcrumPoint = new Complex(23.0);

Don’t Be Cute
    If names are too clever, they will be memorable only to people who share the
    author’s sense of humor, and only as long as these people remember the joke.

    Cuteness in code often appears in the form of colloquialisms or slang. For example,
    don’t use the name whack() to mean kill(). Don’t tell little culture-dependent jokes like
    eatMyShorts() to mean abort().
    
    Say what you mean. Mean what you say.

Pick One Word per Concept
    
    Pick one word for one abstract concept and stick with it.
    
         The name leads you to expect two objects that have very different type as well as
    having different classes.
    
         Sadly, you often have to remember
    which company, group, or individual wrote the library or class in order to remember which
    term was used. Otherwise, you spend an awful lot of time browsing through headers and
    previous code samples.

    The function names have to stand alone, and they have to be consistent in order for you to pick the cor-
    rect method without any additional exploration.

    A consistent lexicon is a great boon to the programmers who must use your code.

 

 

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posted @ 2013-07-25 11:03  尹少爷  阅读(336)  评论(0编辑  收藏  举报