Ninja code
Learning without thinking is useless , thought without learning is perilous .—— Confucius
Ninja programmers used to use these techniques , Sharpen the mind of code maintainers .
Code review masters look for them in test tasks .
Some new developers can sometimes use them better than Ninja programmers .
Read this article carefully , Find out who you are —— A ninja 、 A novice 、 Or a code reviewer ？
Be careful ： Irony detected
Many people try to follow in the footsteps of ninjas . Only a very few succeeded in .
Simplicity is the soul of wisdom
Write the code as short as possible . Show how smart you are .
In programming , Use more clever programming language features .
for example , Take a look at this ternary operator '?'：
// From a famous JavaScript Code intercepted in the library
i = i ? i < 0 ? Math.max(0, len + i) : i : 0;
cool , Am I right? ？ If you write like this , Those who see this line of code and try to understand i What is the value of developers , There will be one “ Happy ” Time . Then I'll come to you to find out .
It's always better to tell him that it's shorter . Guide him into the path of Ninja .
A variable of letters
Tao Yin is nameless . The only way I can do it is to be good at lending .—— Lao tze （ Moral by ）
Another way to speed up programming is , Use single letter variable names everywhere . for example a、b or c.
Short variables are like real ninjas in the forest , I can't find it in a moment . No one can get through the editor “ Search for ” Function to find it . Even if someone does , He can't either “ Decipher ” Give variable name a or b What does it mean .
…… But there is an exception . A real ninja would never be in "for" Use in loop i As a counter . It can be anywhere , But it won't work here . You can look for , You can find a lot of unusual letters . for example x or y.
How cool it is to use an unusual variable , Especially in the long 1-2 page （ If you can , You can write longer ） When used in the circulatory body of . If someone wants to study the inner implementation of the loop , It's hard for him to find variables very quickly x It's actually a cycle counter .
Using abbreviations
If the team rules prohibit the use of a letter and fuzzy naming — Then shorten the naming , Use abbreviations .
like this ：
* list -> lst
* userAgent -> ua
* browser -> brsr
* …… etc.
Only people with really good intuition , To understand such naming . Shorten everything as much as possible . Only people who are really valuable , To maintain the development of this code .
Soar high, Abstraction .
There is no corner ,
Was a late bloomer ,
Great sound is hard to hear ,
The great form has no shape .
—— Lao tze （ Moral by ）
When choosing a name , Try to use the most abstract words . for example obj、data、value、item and elem etc. .
* The ideal name for a variable is data. Use it wherever you can . You bet , Every variable holds data （data）, Right ？
…… however data What to do if it has been used ？ You can try it value, It's also very common . After all , A variable always has a value （value）, Right ？
* Name the variable according to its type ：str、num……
Give it a try . Novices may be surprised — Are these names really useful for ninjas ？ in fact , Helpful ！
One side , Variable names still have some meaning . It shows what's inside the variable ： A string 、 A number or something . But when an outsider tries to understand the code , He will be surprised to find that there is actually no valid information ！ In the end, you can't change the code you think about .
We can debug through code , It's easy to see the type of value . But the meaning of variable names ？ Which string or number does it store ？
If the depth of thinking is not enough , There is no way to understand .
* …… But if we can't find more of them ？ You can add a number ：data1, item2, elem5……
Pay attention to the test
Only a really careful programmer can understand your code . But how to test ？
One way —— Use similar variable names , image date and data.
Mix them as much as you can .
It's impossible to read this code quickly . And if there's a typo …… forehead …… We've been stuck here for a long time , It's time for dinner (⊙v⊙)
Synonyms for intelligence
The hardest thing is to find a black cat in a dark room , Especially if there is no cat .—— Confucius
Yes The same Use of things similar The name of , Can make life more interesting , And show your creativity .
for example , Function prefixes . If a function's function is to display a message on the screen — The name can be display… start , for example displayMessage. If another function shows something else , For example, a user name , The name can be show… Start （ for example showName）.
It suggests that there are subtle differences between these functions , There is no such thing as .
Make an agreement with the other ninjas in the team ： If Zhang San is in his code with display... Let's start with a “ Show ” function , Then Li Si can use render.., Wang Er can use paint.... You can see how interesting and diverse the code has become .
…… Now it's a hat trick ！
For two functions with very important differences — Use the same prefix .
for example ,printPage(page) Function will use a printer （printer）.printText(text) Function to display text on the screen .
Let an unfamiliar reader think about ：“ The name is printMessage(message) Where will the message be placed by the ？ Printer or on screen ？”.
To make the code really stand out ,printMessage(message) The message should be output to a new window ！
Reuse names
The beginning is famous ,
There is also a name ,
I will also know ,
It's not dangerous to know .
—— Lao tze （ Moral by ）
Add new variables only if absolutely necessary .
otherwise , Reuse existing names . Just write the new value into the variable .
In a function , Try using only variables passed as parameters .
So it's hard to determine what the value of this variable is now . I don't know where it came from . The goal is to improve the intuition and memory of people reading code . A less intuitive person has to analyze the code line by line , Track changes in each code branch .
An advanced scheme of this method is , Secretly replace its value in a loop or function .
for example ：
function ninjaFunction(elem) {
// Based on variables elem Carrying out the work 20 Line code
elem = clone(elem);
// also 20 Line code , Now we use clone After elem Variable .
}
Want to use in the second half elem The programmers of will be surprised …… Only during commissioning , After checking the code , He'll find out that he's using cloned variables ！
I often see code like this , Even for experienced ninjas, it's deadly .
The fun of underline
Underline the variable name _ and __. for example _name and __value. If only you know what they mean , That would be great . perhaps , Add these underscores just for fun , It doesn't mean anything , That would be even better ！
Underline is a double shot . First , The code gets longer , Less readable ; also , Your developer partners can take a long time , To find out what underlining means .
Smart ninjas use underscores in one place of the code , Then deliberately avoid using them in other places . This makes the code more vulnerable , And improve the possibility of future errors in the code .
Show your love
Show us your rich feelings ！ image superElement、megaFrame and niceItem Such a name must inspire the reader .
in fact , On the one hand , Seems to have written something ：super..、mega..、nice... But on the other hand — No details were provided . People who read the code can spend an hour or two on paid work , Think hard to find a hidden meaning .
Overlapping external variables
He who deals with the light does not see a thing in the dark ,
Those in the dark can see the central area .
—— Guan Yinzi
For variables inside and outside functions , Use the same name . It's simple , Don't bother to think about a new name .
let user = authenticateUser();
function render() {
let user = anotherValue();
...
... Many lines of code ...
...
... // <-- A programmer wants to use user Variable ……
...
}
Research on render Programmers of internal code may not notice , There's an internal variable user Shielding the outside user Variable .
Then he would assume that user It's still an external variable and use it ,authenticateUser() Result …… The trap is coming out ！ How are you? , The debugger ……
Side effects everywhere ！
Some functions don't seem to change anything . for example isReady(),checkPermission(),findTags()…… They are assumed to be used to perform calculations 、 Find and return data , They don't change any data outside of themselves . This is known as “ No side effect ”.
A very surprising technique is , Apart from the main task , Add a... To them “ Helpful ” action .
When your colleagues see it named is..、check.. or find... When a function of a changes something , There must be a look of stupidity on his face — This will widen your rational boundaries .
Another way to surprise is , Return non-standard results .
Show your original ideas ！ Let call checkPermission The return value of is not true/false, It's a complex object that contains the results of the check .
Those who try to write if (checkPermission(..)) The developer of the , I wonder why it can't work . Tell them ：“ Read the document ”. Then give this article .
Powerful functions ！
The road is wide ,
It can be left or right .
—— Lao tze （ Moral by ）
Don't restrict functions to what is written in the name . Broaden a little .
for example , function validateEmail(email) Sure （ In addition to checking the correctness of the email ） Display an error message and ask to retype the message .
Extra actions should not be obvious in function names . A real ninja would make them invisible in the code .
Combine multiple actions , Protect your code from reuse .
Imagine , Another developer just wants to check the mailbox and not output any information . Your function validateEmail(email) It's not suitable for him . So he won't interrupt your thinking by asking you anything about these functions .
summary
All of the above “ Suggest ” It's all extracted from real code …… occasionally , The code is written by experienced developers . Maybe more experienced than you ;）
* Follow one of them , Your code will be full of surprises .
* Follow a large part of it , Your code will really become your code , No one will want to change it .
* Obey all , Your code will be a valuable example for young developers looking for inspiration .
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