The term scope describes the visibility of variables, functions, and objects in a line of code during runtime. The principle is based on the idea that users should only have access to what they need at that time—and it represents The Principle of Least Access in practice.
Software engineers should understand the difference between local scope and global scope. They should also be able to articulate which situations each access level is best for. Local scope refers to variables that can only be accessed by code inside of the function. On the other hand, global scope variables can be read and changed from anywhere in the code, regardless of the location of the variables.
Code typically runs in order from the first line to the last line. However, oftentimes scripts use conditional structures to change the way that code is executed.
Take a standard website contact form, for example. When a visitor completes the form and clicks submit, the script submits their information and generates a confirmation note for the user. However, if the form is not complete, the conditional structure will generate a note that one or more fields are required.
Coding errors are an inevitable part of the software development process. It doesn’t matter how experienced a programmer is—mistakes will happen. In fact, research has found that software engineers make, on average, “about 15-50 errors per 1000 lines of delivered code.”
Asynchronous programming is a type of parallel programming that enables multiple actions to happen simultaneously. When a user starts an action, the program continues to run until it returns the result. This type of code is quite different from traditional synchronous programming. The standard approach had a user start an action—and the program would cease running until the result was returned. The primary drawback associated with this approach is that a second request will not start until the first is complete.
Since a program can run multiple actions at once, the asynchronous code can improve application performance and software responsiveness. It is important to make sure that potential developers understand the difference between the two approaches. Ask them to explain the differences between the two types of code, as well as which situations each is best used for.
Document Object Model
The best software developers should have an understanding of the most important software security models used throughout the industry. Approaches like the Trusted Software Methodology and the Trustworthy Computing Security Development Lifecycle have decades of data demonstrating their success. Ask potential employees about their experience with popular security models and how they ensure that software security is integrated into every stage of the development life cycle.