common javascript interview questions

25 JavaScript interview questions you need to know 1. Usetypeof bar === "object"JudgmentbarIs an object having potential drawbacks? How can we avoid such disadvantages? UsetypeofThe disadvantage is obvious.instanceof): let obj = {};let arr = [];console.log(typeof obj === 'object'); //trueconsole.log(typeof arr === 'object'); //trueconsole.log(typeof null === 'o

Share common questions about javascript scopes and javascript questions This article will share with you the relevant content about the javascript scope interview

memory, can be controlled by the parameter max_heap_table_size the memory table size, set this parameter, you can limit the memory table maximum size.2. If the data is temporary and required to be immediately available, it can be stored in the memory table.3. Data stored in the memory table, if suddenly lost, will not have a substantial negative impact on the app service.What kinds of data structures are there in the Redis database? 5 Types of data structuresStringWhen using string, redis** doe

(avoid loss of modification) 2) Level two block protocol: increase transaction T on the basis of the first level blocking protocol must read the data R before reading the lock, you can release the read lock after reading (to avoid loss of modification and read dirty data) 3) Level three block protocol: increase the transaction T on the basis of the first level blocking protocol the lock must be read before the data R is read, until the end of the transaction is released (avoid loss of modificat

object. Conversely, when Getfullname () is assigned to the test variable, the context refers to the Global Object (window). This is because test is a property that is implicitly set to the global object. For this reason, the function returns the FullName of the window, that is, the value defined in the first row. Question 5:call () and apply ()Now let you solve the previous problem and make the final Console.log () print Aurelio De Rosa. Answer The problem can change the function context by fo

Java and C common technical interview questions 2015 (Continuous updates ...), 2015 updating 1. Differences between overwrite and overload Overload is an Overload. It uses the same name as an existing member to declare attributes or methods, but the parameter list is different from that of the original member. Override is mainly used for method rewriting between

InC/C ++In the interview process of programmers, many interview questions seem simple, but they need profound basic skills to give a perfect answer. Enterprises require the interviewer to write the simplest strcpy function to see how technically the interviewer has achieved. Can we really write a strcpy function? We all think we can, but the strcpy we write may o

Follow Finddreams Blog: http://blog.csdn.net/finddreams/article/details/44513579The general interview process is followed by the interview, and the technical manager will ask you some questions about the android you're working on, the project you're doing, and the role you're playing in the project. Today I will give you some of the

simple example: 7. What media labels are available in addition to audio and VIDEO,HTML5?HTML5 provides strong support for multimedia, with the following tags supported in addition to audio and video tags: 8. What is the use of HTML5 Canvas elements?the Canvas element is used to draw a graphic on a Web page, and the element tag is powerful in that it can be graphically manipulated directly on HTML . 9, HTML5 storage types? HTML5 can store data locally, It was used in the past with coo

process is more standardized, the amount of manual encoding is reduced, and the encoding efficiency is improved. At the same time, when data is updated, sometimes the component is not required, but it also needs to be re-drawn, which affects the efficiency. Generally, they are used only when building complex projects with multiple interactions and data streams. What are the disadvantages of redux? The data required by a component must be transmitted by the parent component, but cannot be dire

Android development interview post-3. common Android advanced pen questions, android advanced Follow finddreams blog: http://blog.csdn.net/finddreams/article/details/44301359In the previous article, we have learned some basic questions about the Android test. Android development i