LUKI NOTES

When we are maintaining variables in our Javascript code, we must already know about the scope that determines the visibility of variables. There are three types of scope which are block, function, and global scope. A variable defined inside a function is not visible (accessible) from outside the function. But, the variable is visible to any blocks or functions inside the function. When a function is created, it has access to variables in the parent scope and its own scope, and it is known as closure scope. For example, if we create a function (child) inside another function (parent), in the creation time the child function will also have access to variables declared in its parent. Another way to think of closure is that every function in JavaScript has a hidden property called "Scope", which contains a reference to the environment where the function was created. The environment consists of the local variables, parameters, and arguments that were available to the...

In cybersecurity, a threat is the potential occurrence of an undesirable event that can eventually damage or disrupt the operational and functional activities of a company or organization. Some examples are an attacker stealing sensitive data, infecting a system with malware, and data tampering. In order to realize their intentions, threats need vectors. A threat vector is a medium through which an attacker gains access to a system by exploiting identified vulnerabilities. Some most common threat vectors used by adversaries are as follows. Direct/physical access : By having direct access to our computing devices, the attacker can perform many malicious activities like installing malicious programs, copying a large amount of data, modifying device configuration, and so on. Protection : We should implement strict access control and restriction. Removable media : Devices like USB flash drives, smartphones, or IoT devices may contain malicious programs...

One library that is quite popular to allow our application to interact with the GraphQL server is Apollo Client ( @apollo/client ). It has support for several popular client libraries including React. It also provides cache management functionality to improve the performance of the application when interacting with GraphQL. Rather than integrating another library to manage our application state, we can leverage what Apollo Client already has to maintain the state. The solution is achieved by creating a customised query to load the result from a local variable or storage. Then, the query is executed like other queries using useQuery() . The steps are as follows. Create a local query that will read data only from the cache. Create a cache that defines a procedure for the query to read data from local values. Call the query anytime we want to read the state value. For instance, we want to read the information of the current user that has successfully logged in...