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  660

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  1198

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  1338

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  858

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  1354

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  1406

functionunset()

The tutorial says: 3. Use the function unset() to destroy the variable, but the code demonstration uses var_dump(); are unset() and var_dump() the same function? Address: //m.sbmmt.com /code/985.html

Rebecca 2022-10-19 11:04:45 0  1  1503

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  1444

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  657

javascript - What is the difference between a line of code placed inside a function and outside a function?

//Inside function {code...} //Outside function {code...} Why?

我想大声告诉你 2017-06-28 09:22:31 0  1  788

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  587

What is the difference between functions and variables?

What is the difference between functions and variables? Why appear together? Functions and variables, all of them are faint.

武汉蜗牛 - Jack Li 2019-09-08 11:38:24 0  8  2504

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  582

javascript - Encapsulate the repeated parts of these two functions into one function?

{Code...} The two functions are very similar (repeated). How to encapsulate the repeated parts of these two functions into one function?

大家讲道理 2017-05-19 10:09:46 0  3  668

There is no main function in javascript

There is no main function in javascript. The main function is often used in Java and C languages. It is also called the main function and is required to have a return value. Returning 0 means that the program is successfully executed normally, and returning a non-0 value means that the program ends ...

手机用户757625696 2022-04-06 13:51:04 0  0  1206

javascript - How to bind a callback function to a variable

Can Javascript bind a callback function to a variable? That is: when the value of this variable changes, the callback function is triggered and the content in the callback function is executed.

高洛峰 2017-06-26 10:53:29 0  3  944

PHP substr() function

How to understand the usage of PHP substr() function: If the start parameter is a negative number and length is less than or equal to start, then length is 0. This sentence

ringa_lee 2017-05-24 11:30:51 0  2  822

function

If you declare a function say(); and then var a = say; is the address or value of say passed to a at this time?

巅峰之前 2019-09-17 09:35:44 0  2  1308

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  572

vim shortcut key to delete function

Does anyone know how to quickly delete the entire function in vim (C and js functions, anyway, it’s curly braces {})? V selects multiple lines to delete or counts the number of lines in the function and then Ndd, which is not convenient when the function is very long.

天蓬老师 2017-05-16 16:36:33 0  1  704