Summary of JavaScript shorthand tips

Source: Internet
Author: User

In daily work, javascript some common shorthand skills, will directly affect our development efficiency, now the common skills are organized as follows:

1. Null (null, undefined) validation

When we create a new variable, we usually verify that the value of the variable is empty (null) or undefined (undefined). This is an often-considered validation for JavaScript programming.

Non-optimized code:

if NULL ") {Let variable2 = variable1;}

Optimized code:

In the Google Explorer developer panel under the console:

2. Arrays

Non-optimized code:

New Array (); a[0"myString1"; a[1"myString2"; a[2"myString3";

Optimized code:

Let a = ["MyString1", "MyString2", "MyString3"];

3. If true: Else optimization

Non-optimized code:

Let big; if Ten  true;} Else  false;}

Optimized code:

Let big = x > 10? True:false;

In the Google Explorer developer panel under the console:

4. Variable declaration

Non-optimized code:

3;

Optimized code:

Let x, Y, z=3;

5. Simplification of assignment statements

Non-optimized code:

x=x+11; y=y*;

Optimized code:

X++;minuscount--;y*=10;

Assuming x=10,y=5, then the basic arithmetic operation can be done using the following shorthand method:

In the Google Explorer developer panel under the console:

6. Avoid using RegExp objects

Non-optimized code:

var New REGEXP ("\d+ (.) +\d+","igm"= re.exec ("padding 01234 text text 56789 padding"//" 01234 text text 56789 "

Optimized code:

var result =/d+ (.) +d+/igm.exec ("padding 01234 text text 56789 padding"); Console.log (result); "01234 text text 56789"

7. If condition Optimization

Non-optimized code:

if true)

Optimized code:  

if (likejavascript)

8. Alternatives to CharAt ()

Non-optimized code:

" myString ". CharAt (0);

Optimized code:

"MyString" [0]; Return ' m '

Summary of JavaScript shorthand tips

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