Problem Solving and Programming

• Local variables have limited scope which means that they can only be accessed within the block of code in which they were defined
• local variables with the same name can exist in different subroutines and will remain unaffected by each other
• g local variables is considered to be good programming practice because it ensures subroutines are self-contained, with no danger of variables being affected by code outside of the subroutine
• Global variables, on the other hand, can be accessed across the whole program
• global variables is not recommended because they can be unintentionally overwritten and edited
• . As global variables are not deleted until the program terminates, they require more memory than local variables which are deleted once the subroutine has been completed
• Modular programming is a programming technique used to split large, complex programs into smaller, self-contained modules
• A modular design also makes it easier to divide tasks between a team and manage, whilst simplifying the process of testing and maintenance, as each component can be dealt with individually
• r technique used to modularise programs is called the top-down approach, in which the problem is continually broken down into sub-problems, until each can be represented as an individual, self-contained blackbox which performs a certain task
• Procedures and functions are both named blocks of code that perform a specific task. While pro
• While procedures do not have to return a value, functions must always return a value. Procedures can return multiple values whereas a function must return one, single value
• Procedures are typically given data as parameters for manipulation while functions commonly make use of local variables
• When parameters are passed into a subroutine, they can be passed either by value or by reference
• When a parameter is passed by value, it is effectively treated as a local variable; a copy of the value is passed to the subroutine and discarded at the end therefore its value outside of the subroutine will not be affected.
• Passing by reference means that the address of the parameter is given to the subroutine, so the value of the parameter will be updated at the given address.
• An Integrated Development Environment, or IDE, is a program which provides a set of tools to make it easier for programmers to write, develop and debug code
• Debugging tools Some IDEs also provide run-time detection of errors with a guide as to where in the code they are likely to have occurred through line numbers and highlighting.
• Breakpoint IDEs allow users to set a point in the program at which the program will stop. This can either be based on a condition or set to occur at a specific line. This can help to pinpoint where an error is occurring
• Source code editor The editor aims to make the coding process easier by providing features such as autocompletion of words, indentation, syntax highlighting and automatic bracket completion
• Stepping This allows you to monitor the effect of each individual line of code by executing a single line at a time