Summary of articles on php eval function

Suppose there is a dictionary in python as follows: x={'a':'1,2,3', 'b':'2,3,4'} needs to be merged into: x={'c':' 1,2,3,4'} needs to do three things: 1. Convert the string into a numerical list 2. Merge the two lists and add new key values ​​3. Remove duplicate elements Step 1 through the commonly used function eval () can be done. In the second step, you need to add a key value and add elements. In the third step, you can use the properties of the set collection to achieve the effect of deduplication, but in the end you need to convert the set collection into a list list. The code is as follows: x={'a':'1,2,3','b':'2,3,4'} x['c']=list(set(eval(x['a'])+eval(x['b']))) del x['a']1.

1. php eval() function article recommendation

Introduction: Suppose there is a dictionary in python as follows: x={'a':'1,2,3', 'b':& #39;2,3,4'} needs to be merged into: x={'c':'1,2,3,4'} Three things need to be done: 1. Convert the string into a numerical list 2. Merge the two lists and add a new key value 3. Remove duplicate elements. The first step can be done through the commonly used function eval(). The second step requires adding a key value and adding elements. Step 3 Use s...

2. Analyze the usage of DataBinder_Eval

Introduction: -------All uses of DataBinder------------------ //Bind fields //Implement automatic numbering Commonly used methods

3. Instance code for merging dictionary key values ​​and removing duplicate elements using Python

Introduction: Suppose there is a dictionary in python as follows: x={'a':'1,2,3', 'b':'2 ,3,4'} needs to be merged into: x={'c':'1,2,3,4'} Three things need to be done: 1. Convert the string into a numerical list 2. Merge the two lists and Add a new key value 3. Remove duplicate elements. The first step can be done through the commonly used function eval(). The second step needs to add a key value and add elements. The third step uses the properties of the set collection

4. WeChat public platform development method to ensure long-term validity of access_token

##Introduction: This article introduces the method of developing WeChat public platform to ensure the long-term validity of access_token

5. Detailed code explanation of the calculation formula of string format through eval in php

Introduction: Sometimes we have a commission formula for each product, and this calculation formula The formula is stored in the table in string format. When we use this calculation formula, it is not as simple as what we wrote: $a=2+3*5; to calculate the result, but it is a string. Therefore, we must convert the string into a result that we can process

6. A brief introduction to the execution efficiency of JavaScript

Introduction: Javascript is a very flexible language. We can write various styles of code as we like. Different styles of code will inevitably lead to differences in execution efficiency. The development process is scattered here and there. I came into contact with many methods to improve code performance, and sorted out the common and easy-to-avoid problems. Javascript's own execution efficiency. Scope chain, closure, prototype inheritance, eval and other features in Javascript not only provide various magical functions but also bring Various efficiency problems arise, and careless use will lead to low execution efficiency. 1. Global import we will use more or less in the coding process..

7. XML instance tutorial: detailed explanation of nodeName, nodeValue and nodeType attributes

Introduction: This article introduces the nodeName, nodeValue and nodeType attributes in detail

8 . Example of Java implementation of state (State) pattern

#Introduction: /*** @author stone*/public class WindowState { private String stateValue; public WindowState(String stateValue) { this.stateValue = stateValue; } public String getStateValue() { retur

9. SpringMVC Learning Series (5) Data Binding-2

Introduction: In Series (4) we We have introduced how to use @RequestParam to bind data. Let’s take a look at how to use other data binding annotations. 1.@PathVariable is used to bind URL template variable values. We have already introduced how to use this in series (3) and will not go into details here. 2.@CookieValue is used to bind data in Cookie. Below we use the sessionId in the cookie for testing: In DataBindContro

10. SpringMVC Learning Series (4) Data Binding-1

Introduction: In series (3) we introduced how requests are mapped to an action. The next step is of course how to obtain The data in the request leads to what this article is going to talk about—data binding. First, let’s take a look at the annotations for binding data: 1. @RequestParam, binds a single request data, which can be data in the URL, data submitted by the form or uploaded file; 2. @PathVariable, binds the URL template variable value ; 3. @CookieValue, bind the number of cookies

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