Having taken some time off, I am excited to start Tech Tuesdays back up. We will continue looking at programming and the next topic are more complex data types which are also referred to as data structures. If you have been following the programming series, you may recall that we already had three separate posts dealing with data types. These introduced the concept of data types and discussed why they matter and how they are implemented. But those posts dealt with simple types of data such as...

Having taken some time off, I am excited to start Tech Tuesdays back up. We will continue looking at programming and the next topic are more complex data types which are also referred to as data structures. If you have been following the programming series, you may recall that we already had three separate posts dealing with data types. These introduced the concept of data types and discussed why they matter and how they are implemented. But those posts dealt with simple types of data such as...

In the last two Tech Tuesdays we have learned about how functions let us define new words in a programming language and how arguments and other local variables are restricted to the scope of the function. Today we will take another look at arguments and how exactly information is passed into the function. Then Tech Tuesday will take the rest of the summer off and resume after Labor Day as I will take my usual late August break from blogging. To motivate today’s discussion take a look at the f...

In the last two Tech Tuesdays we have learned about how functions let us define new words in a programming language and how arguments and other local variables are restricted to the scope of the function. Today we will take another look at arguments and how exactly information is passed into the function. Then Tech Tuesday will take the rest of the summer off and resume after Labor Day as I will take my usual late August break from blogging. To motivate today’s discussion take a look at the f...

Today on Tech Tuesday we are diving into Data Structures. The idea of a data structure that combines multiple attributes to describe a thing, goes back as far as the 1960s and possibly earlier. Both the COBOL and ALGOL programming languages already had this concept and IBM’s mainframe operating systems such as DOS/360 had built in storage support (in form of ISAM files). At the time most computing was super pragmatic and motivated by solving business problems – in fact COBOL stands for COmmon...

Today on Tech Tuesday we are diving into Data Structures. The idea of a data structure that combines multiple attributes to describe a thing, goes back as far as the 1960s and possibly earlier. Both the COBOL and ALGOL programming languages already had this concept and IBM’s mainframe operating systems such as DOS/360 had built in storage support (in form of ISAM files). At the time most computing was super pragmatic and motivated by solving business problems – in fact COBOL stands for COmmon...

Last Tech Tuesday we learned about functions as a way to define our own words in a programming language. We saw that functions take arguments and return results back to where the function was used in the program. We refer to this transfer of control of program execution from the current code to the code inside the function as a function call or a function invocation (the function is called or invoked). As promised at the end of that post, today we will take a closer look at how the arguments ...

Last Tech Tuesday we learned about functions as a way to define our own words in a programming language. We saw that functions take arguments and return results back to where the function was used in the program. We refer to this transfer of control of program execution from the current code to the code inside the function as a function call or a function invocation (the function is called or invoked). As promised at the end of that post, today we will take a closer look at how the arguments ...

Last time in the Tech Tuesday cycle on programming we saw that so-called reserved words have special meaning. They effectively constitute the built-in vocabulary of a programming language. Now let’s go all the way back to the basic analogy that I used for the overview post: programming is telling a computer what to do, which is very much like telling a person what to do. One of the expressive abilities that is required for that are conditionals, as in: if the front door is locked, then go aro...

Last time in the Tech Tuesday cycle on programming we saw that so-called reserved words have special meaning. They effectively constitute the built-in vocabulary of a programming language. Now let’s go all the way back to the basic analogy that I used for the overview post: programming is telling a computer what to do, which is very much like telling a person what to do. One of the expressive abilities that is required for that are conditionals, as in: if the front door is locked, then go aro...

In the last two posts we looked at control structures as part of the programming series here on Tech Tuesdays. We saw that loops let us repeat a sequence of instructions, which is one way of having to avoid writing the same code over and over again. Today we will learn about another and more powerful technique: the definition of new words that can then be used anywhere in the program. You may recall the example of nautical terms from the post on programming languages:For instance, if I tell a...

In the last two posts we looked at control structures as part of the programming series here on Tech Tuesdays. We saw that loops let us repeat a sequence of instructions, which is one way of having to avoid writing the same code over and over again. Today we will learn about another and more powerful technique: the definition of new words that can then be used anywhere in the program. You may recall the example of nautical terms from the post on programming languages:For instance, if I tell a...

This will be the third and final part of talking about data types as part of the programming cycle on Tech Tuesdays. Part 1 introduced the basic issue. Part 2 went under the hood and showed how explicit type declarations are one way to solve the problem. Today we will look at another approach and none of this will make much sense if you haven’t read the first two parts. Last week I showed how an address table can be used to keep track of what the current value of a variable is. I then also sh...

This will be the third and final part of talking about data types as part of the programming cycle on Tech Tuesdays. Part 1 introduced the basic issue. Part 2 went under the hood and showed how explicit type declarations are one way to solve the problem. Today we will look at another approach and none of this will make much sense if you haven’t read the first two parts. Last week I showed how an address table can be used to keep track of what the current value of a variable is. I then also sh...

Last Tech Tuesday we got started on data types as port of the ongoing cycle on programming. This post will not make sense without reading Part 1, so if you haven’t you should go back and do that now. We encountered the problem of “adding” two variables where one holds a number and the other holds some text. Today we will dig a bit deeper into this problem. Let’s start by looking at the question what it even means for a variable to hold a value. As I explained in the post on literals, constant...

Last Tech Tuesday we got started on data types as port of the ongoing cycle on programming. This post will not make sense without reading Part 1, so if you haven’t you should go back and do that now. We encountered the problem of “adding” two variables where one holds a number and the other holds some text. Today we will dig a bit deeper into this problem. Let’s start by looking at the question what it even means for a variable to hold a value. As I explained in the post on literals, constant...

Just as a reminder, on Tech Tuesday I am currently going through what will be a pretty long cycle on programming. The overview post sets out a series of questions to be answered. The most recent posts on Variables, Constants and Literals and then on Data Types (Parts 1, 2 and 3) provide some of the basics for answering overview question 4 about how programs can refer to concepts as opposed just concrete things. There is a lot more to say about this but first we will turn to overview question ...

Just as a reminder, on Tech Tuesday I am currently going through what will be a pretty long cycle on programming. The overview post sets out a series of questions to be answered. The most recent posts on Variables, Constants and Literals and then on Data Types (Parts 1, 2 and 3) provide some of the basics for answering overview question 4 about how programs can refer to concepts as opposed just concrete things. There is a lot more to say about this but first we will turn to overview question ...

I was originally planning to write today’s Tech Tuesday post about how we can define our own words in a programming language. But then I noticed an important omission in last week’s post on control structures. I didn’t really explain how we can have multiple statements in either a loop or in a branch of program execution. I just kind of snuck that into the following example:

I was originally planning to write today’s Tech Tuesday post about how we can define our own words in a programming language. But then I noticed an important omission in last week’s post on control structures. I didn’t really explain how we can have multiple statements in either a loop or in a branch of program execution. I just kind of snuck that into the following example: