Differences between the three-object operator and ifelse in JS and examples _ javascript tips-js tutorial

This article analyzes the differences between the three-object operator and ifelse in JS through examples. It is a very good article. We recommend it to you here. Today I wrote a small demo of image carousel and used it to determine

First try if elseThe Code is as follows:

The Code is as follows:

If (n> = count-1 ){
N = 0;
} Else {
N ++;
}

After the code is written, prepare to optimize the code and change the code segment to the three-object operator.

The Code is as follows:

N = n> = (count-1 )? N = 0: n ++

Different Results

Then I studied the differences between the two, and concluded that the three-object operation has a return value, and if else has no return value.

The following test is performed:

The Code is as follows:

Var n = 1;
If (n> 1 ){
N = 0;
} Else {
N ++;
}
Console. log (n );

Output result: 2

Three-object operationAs follows:

The Code is as follows:

Var n = 1;
N = n> 1? 0: n ++;
Console. log (n );
Output result: 1

Insert a piece of other content: the difference between ++ n and n ++: Simply put, they all use n auto-increment 1. The difference is that n ++ adds 1 to the statement after execution, while ++ n executes the statement after n + 1.

So what about ++ n?

If else statement

The Code is as follows:

Var n = 1;
If (n> 1 ){
N = 0;
} Else {
++ N;
}
Console. log (n );
Output result: 2

Result

The Code is as follows:

Var n = 1;
N = n> 1? 0: ++ n;
Console. log (n); the output result is: 2

We can see the difference between if else and the three-object operation ~~~

N ++ and ++ n have no difference in this verification, because if else is after the calculation result, n is not returned, and no return value is returned.

However, for the three-object operation, the n value returned by n ++ is n itself, and the n value returned by ++ n is n + 1.

After reading this article, do my friends have a new understanding of the Three-object operator in js and the if else operator.