How can a function within a function call a variable of the parent function?

var_dump(function_exists('b')); // false function a(){     $var = 123;     function b(){      &nb

喵~ 2022-12-05 19:48:12 0  0  622

function function function

The teacher told me where to find the functions provided by WeChat?

小李飞刀 2018-05-14 21:27:13 0  2  1167

javascript - When adding a new function to a function, should you choose to extend the original function or create a new function~

If you extend the original function, you have to add parameters and if. This causes more judgment when using the normal function. I am not happy. When I create a new function, I declare a piece of memory for it, which consumes more memory~

ringa_lee 2017-05-19 10:23:44 0  2  536

PHP nested function and anonymous function scope issues

{Code...} All functions and classes in PHP have global scope and can be defined within a function and called outside it, and vice versa. Why can function b obtain the local variables of function a by passing parameters? {Code...} Similarly, why does the anonymous function also obtain external variab...

phpcn_u1582 2017-05-18 10:45:34 0  1  626

How does a js external function call the object in the callback function?

!function(a,b){ f = b();//Here F is the object }(this,function(){ ....... ....... }) function e(){ //How to call the object F in the function e //for example &

按键盘手指磨破皮 2020-04-09 18:07:44 0  1  1013

Does the vim plug-in youcompleteme have the function of "finding all functions that call this function based on a function definition"?

I just started using vim and installed youcompleteme. It is possible to jump to the function definition, but it seems that you cannot find where the function is called based on where the function is defined. Please help me, do you have any good solutions?

迷茫 2017-05-16 16:38:05 0  2  1043

javascript - Questions about function closures and passing functions as parameters

1. Description: I want to get a function array result. First, the func function adds an anonymous function to the array result (each anonymous function saves its own num). But I pass in the anonymous function after return with parameters, which is equivalent to just It's just a replacement, why are ...

世界只因有你 2017-06-26 10:50:31 0  3  817

javascript - How to specify a function function in the data attribute of html5?

Could you please specify a function function in the data-* attribute? For example, if I write like this, I will get an error formatter is not a function: {code...}

学习ing 2017-06-24 09:43:53 0  6  1064

mysqli function

When using mysqli_num_rows() and other functions in the TP5.1 framework, an error will be reported. Can these functions not be used on TP?

林瑞程 2019-09-07 21:00:50 0  5  1379

javascript - How does the callback function access the value under the current function?

I defined an array variable in the function, which contains 6 elements, and then called the callback function in the function. The value of the array variable cannot be accessed in the callback function, but the length attribute can be accessed. I feel very confused and don't know how to solve it. {...

大家讲道理 2017-05-16 13:35:48 0  4  559

Problems when calling private function test() through public function getSalary()

  public function getSalarya()    {        $res = $this->test();        return $res;    }    private function test(){ 

孙痴慢 2018-10-12 06:40:47 1  4  1019

javascript - What is the difference between a callback function and a normal calling function?

The definition of a callback function is to pass function b as a parameter to a for execution. At this time, b is the callback function. I suddenly have a question, what is the difference between it and calling b directly in function a? I wrote a demo myself {code...} It takes about 3 seconds to see...

欧阳克 2017-06-26 10:53:07 0  2  1415

Advantages of overriding functions?

{Code...} This function rewrites itself after the first call, thus avoiding unnecessary repetition of operations each time it is called. How to understand this specifically? Isn’t the function execution thread the same before and after rewriting the function?

女神的闺蜜爱上我 2017-06-12 09:29:12 0  4  779

javascript function

{Code...} Why does the above code output 1? After foo() is run, this is output. This is the window object. Does the getName in foo() also become a global function expression? And The following var getName is also a function expression; why the printed result is 1; foo,...

给我你的怀抱 2017-06-26 10:53:22 0  6  767

What is the difference between directly assigning a function to a variable and referencing a function?

What is the difference between directly assigning a function to a variable and referencing a function? For example: Fragment 1 and Fragment 2 Fragment 1 {Code...} Fragment 2 {Code...} The function in onclick in Fragment 1 allows access to the variables in fn, but the onclick function in Fragment 2 d...

大家讲道理 2017-05-19 10:33:08 0  2  535

Function syntax issues

echo '4. Use function to create a self-executing function:<br>'; echo (function ($a,$b){ return $a.'+'.$b.'='.($a+$b); })(20,30);How to display Parse error: syntax error, unexpected '

phpcn_u60427 2017-12-05 19:11:51 0  2  1205

ES 2017: async function vs AsyncFunction object vs async function expression

I just read about async functions and found some similar features for ES2017. It's causing a lot of confusion, and I just want to ask: What's the difference between asyncfunction, AsyncFunction (used to create an async function), and an async function expression (which I think is just another async ...

P粉459440991 2024-03-25 23:44:59 0  1  411

Should one avoid declaring functions within functions (except for intentional closures)?

{Code...} The function test is declared each time it is clicked, and then the click callback is executed and GCed. If the dom is clicked more than once, then each click callback has one more function declaration. I remember that it is not in the jshint specification. Allow function declarations to b...

迷茫 2017-05-19 10:23:40 0  3  572

When javascript function declaration is promoted, will the function body be promoted together?

When javascript function declaration is promoted, will the function body be promoted together? If not, there are the following counterexamples: {Code...} If yes, there are the following counterexamples: {Code...} The first example shows that the function body is also promoted. If you follow this ide...

PHP中文网 2017-05-19 10:43:15 0  10  729

Using JavaScript function calls

I want to call a JS function from Swift and I want to get the result of the JS in Swift. I have a lot of functions that need to be called from Swift. These functions may or may not contain parameters. You also need to include a closure for the result.

P粉118698740 2023-08-15 17:25:19 0  1  549