Function() function object in JS

The Object() constructor can be seen as: var Object=new Function(); the Array() constructor can be seen as: var Array=new Function();....Then: the Function() constructor can be seen What to do is: var Function=new Function()?Create yourself? There are also categories...

欧阳克 2017-06-12 09:29:33 0  3  806

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  614

Calling a function without using print(function()) format? ?

Calling a function without using print(function()) format? ? Can direct functions (parameters) be used?

力 2020-07-23 00:07:01 0  1  1283

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  1194

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  519

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  999

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  604

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  1042

javascript - Problem with function parameter default value being function in ES6?

I have a lot of confusion about the situation where the default value of a function parameter is a function, such as {code...} According to Ruan Yifeng's es6 introduction, I know that if the function parameter is a default value, there will be a block-level scope wrapping the parameter first, and af...

阿神 2017-07-05 11:09:13 0  4  1310

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  1012

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  552

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  717

PDO columnCount function

Is it possible to use the columnCount function to calculate the number of returned results? This function directly returns the number of query result columns. If not, it returns 0.

**军 2019-07-09 09:59:52 0  2  1142

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  753

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  1403

length attribute in js function

For custom functions: function fun(a,b) { {code...} } Print the window object in the chrome development tool and find that there is a custom function fun and its own function getComputedStyle. The formal parameters of the fun function are Two, so the length attribute is 2, and the getComputedStyle f...

曾经蜡笔没有小新 2017-06-14 10:53:55 0  2  976

Why does reassigning a function name within a function body change its behavior?

I came across this function while reverse engineering some JavaScript: functionfun1(){constarr=["a","b","c","d","e"];fun1=function(){returnarr;}; returnfun1();} To me it looks redundant. This code seems to: declare an array arr. in function

P粉270891688 2024-01-16 22:35:06 0  1  458