A three-object operator problem

{Code...} does not understand the result. why is it & quot; excessive & quot ;? Q &

$a = 5;$b = 10;echo ($a) ? ($a == 5) ? 'yay' : 'nay' : ($b == 10) ? 'excessive' : ':('; 

Why is it "excessive "? Q &

Reply content:

$a = 5;$b = 10;echo ($a) ? ($a == 5) ? 'yay' : 'nay' : ($b == 10) ? 'excessive' : ':('; 

Why is it "excessive "? Q &

Modify the value and analyze it based on the result.

//#1 excessive$a = 5;$b = 10;echo ($a) ? ($a == 5) ? 1 : 0 : ($b == 10) ? 'excessive' : ':('; //#2 :($a = 3;$b = 10;echo ($a) ? ($a == 5) ? 1 : 0 : ($b == 10) ? 'excessive' : ':('; //#3 excessive$a = 0;$b = 10;echo ($a) ? ($a == 5) ? 1 : 0 : ($b == 10) ? 'excessive' : ':('; //#4 :($a = 0;$b = 9;echo ($a) ? ($a == 5) ? 1 : 0 : ($b == 10) ? 'excessive' : ':('; 

It can be seen that $ a is executed when it is true ($ a = 5 )? 1: When 0 is false, run $ B = 10.
If this result is true, excessive is returned. if it is false, return :(

In order to facilitate reading, it is best to ($ a = 5 )? 1: 0. add parentheses.

I can only say that js runs out.yay

Is PHP executed like this?

($a ? ($a == 5 ? "yay" : "nay") : $b == 10) ? "excessive" : ":(";

It would be easier to write code by yourself or add a bracket group. for example, the following should be the same result as javascript.

echo $a    ? ($a == 5 ? "yay" : "nay")     : ($b == 10 ? "excessive" : ":(");

If I guess it is correct, I should look at it later and divide the statement.

The division can be simplified
Echo 'yay '? 'Excessive ':':(';

In this way, the result will change.

$ A = 5: yay is returned.

($ )? ($ A = 5 )? 'Yay': 'nay': ($ B = 10 )? 'Excessive ':' :( '; you read the statement from left to right, but the machine does not read it like this ($ )? ($ A = 5 )? 'Yay': 'nay': ($ B = 10 )? 'Excessive '):' ('; the computer head is dizzy.

$? ($ A = 5? 'Yay': 'nay'): ($ B = 10? 'Excessive ':' ('); will it be written like this later?

In terms of language design, js re-outputs, while php re-computing.
Similar differences include the calculation result of the & operator and | operator, and the result after null is converted into a string.