JavaScript writes maintainable code

The basic formatting indentation level is 4 spaces indentation, and it is best to unify tabs to 4 characters. An example of an error caused by a trailing semicolon at the end of a statement.

//原始代码function getData() {    return     {        title:"Maintainable JavaScript",        author:"Nicholas C. Zakas"    }
//分析器会它理解function getData

Basic formatting

Indentation level

4个空格缩进，最好统一tab为4个字符。

End of statement

结尾分号

Example of error

//原始代码function getData() {
    return 
    {
        title:"Maintainable JavaScript",
        author:"Nicholas C. Zakas"
    }//分析器会它理解function getData() {
    return;
    {
        title:"Maintainable JavaScript",
        author:"Nicholas C. Zakas"
    };
}

This problem can be fixed by moving the opening curly brace to the same line as return.

//这段代码工作正常，尽管没有用分号function getData() {
    return {
        title:"Maintainable JavaScript",
        author:"Nicholas C. Zakas
    }
}

The length of the line

80个字符

Line break

通常我们会在运算符后换行，下一行会增加两个层级的缩进（8个字符）

Exception: When assigning a value to a variable, the position of the second line Should be aligned with the position of the assignment operator, for example

var result = something + antherThing + yetAnotherThing + somethingElse + 
             anotherSomethingElse;

empty line

• between methods

• Between local parts of a method and statements

• Before multi-line or single-line comments

• Between logical fragments within a method Insert blank lines between spaces to improve readability

##Basic formatting

Indentation level

4个空格缩进，最好统一tab为4个字符。

End of statement

结尾分号

Example of error

//原始代码function getData() {
    return 
    {
        title:"Maintainable JavaScript",
        author:"Nicholas C. Zakas"
    }//分析器会它理解function getData() {
    return;
    {
        title:"Maintainable JavaScript",
        author:"Nicholas C. Zakas"
    };
}

This problem can be fixed by moving the opening curly brace to the same line as return.

//这段代码工作正常，尽管没有用分号function getData() {
    return {
        title:"Maintainable JavaScript",
        author:"Nicholas C. Zakas
    }
}

The length of the line

80个字符

Line break

通常我们会在运算符后换行，下一行会增加两个层级的缩进（8个字符）

Exception: When assigning a value to a variable, the position of the second line Should be aligned with the position of the assignment operator, for example

var result = something + antherThing + yetAnotherThing + somethingElse + 
             anotherSomethingElse;

empty line

• between methods

• Between local parts of a method and statements

• Before multi-line or single-line comments

• Between logical fragments within a method Insert blank lines in between to improve readability

The above content is maintainable code written in JavaScript. I hope it can help everyone.

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Common JavaScript memory leaks

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