• Merge two arrays according to the category ID into one array to process the cascading menu


    Title description:Array one: arr = [ {categoryid: 1, title: “Language”}, {categoryid: 2, title: “Music”} ] Array two: brr= [ {courseid: 1, categoryid: 1, title: “Introduction to Writing”}, {courseid: 2, categoryid: 1, title: “Advanced Composition”}, {courseid: 3, categoryid: 2, title: “Rock Music Appreciation”}, {courseid: 4, categoryid: 2, title: “Popular Songs”} ] Need to make a secondary […]

  • In-depth understanding of JavaScript – array


    In our previous series, we used the built-in constructorObjectStart to talk about it, and derive various knowledge points from it. Then we talk about another big constructorFunction, which also leads to knowledge points comparable to Object. After these two, the author thinks that the building of JavaScript has been built, but there are still two […]

  • In-depth understanding of JavaScript – loops come here


    It really hurts to write this because my heart is not here anymore. It took a week of back and forth to pry the keyboard circular assembly order There are various loops in JavaScript, such as for, for(reverse), for…in, for…of, forEach, map, etc. What are the characteristics of each of these loops? for loop This […]

  • js array operations – object arrays are grouped according to a same field


    Let’s talk nonsense Recently, in actual business, it is necessary to write a method to re-program objects with equal field values ​​into an array according to an identical field of each object in the array, and return a nested array object to make a special summary.Of course, it should be noted that during the development […]

  • Review – es6 grammar


    There is a problem with the computer these days, I have been working on it, and the thesis is approaching, and it is time to get it. There is a big project in the previous node, which has been completed. Now I am going to continue the review from the last review until this project. […]

  • [C programming] 06 – Array


    In order to efficiently process large batches of data, arrays are introduced: An array is a collection of ordered data. The arrangement of data in the array is regular, and the subscript represents the serial number of the data in the array. An array name and subscript are used to uniquely identify elements in an […]