The second good look of HTML
There is always an excuse to escape, and there is always a way to succeed!
How does js determine whether a json object is empty? Details of the js callback function - Technical article
In development and design, people often have to distinguish between non emptiness, but there are several unique basic data types in JavaScript: undefined and null Null: null type, indicating "null value", indicating an empty target needle. Apply the actual operation of typeof to obtain "object", which is a unique target value. – Undefined: undefined kind. When an argument is declared not reset, its value is undefined. 1. The difference between null and undefined. 2. Specify whether the independent variable is undetermined
How to use Mac split screen software - Apple split screen uses two software - Technical article
Think the parallel processing ability on the Mac is limited? This application software can also help you improve the working efficiency of macOS. In order to work efficiently on your MacBook, you may have to solve many daily tasks in many software at the same time. However, the iPhone still shows a limited set of multiple tasks on the MacOS. For example, the split screen function is limited to two dialog boxes, and is applicable to smaller screens. This is also the best multi task iPhone application process. Come and have a look with Xiao Bian! 1. Magnet standard mac dialog auto tuning auxiliary software. Ma...
AC 380v power calculation formula - formula must be learned by electrician for wiring - technical article
Grasping the calculation method well is the work ability that the electrical equipment staff should have, but it is not convenient to search when using various formulas to calculate. Here, we sort out and collect some common formula calculation and formula calculation, and give examples and expressions. 1. Calculation of power circuit current of lighting fixtures and selection of circuit breakers. Formula calculation: The fluorescent lamp can measure the current by dividing the output power by the working voltage. Measure and calculate the current of fluorescent tubes, excluding the working pressure of switching power supply, and calculate the power factor (except environmental protection and energy-saving fluorescent tubes); The safety knife switch must also be 1.5 times of the rated air volume; indicate...
