OverSimplified: Variables

Welcome! In this series, I try to oversimplify CS concepts in an attempt to help us all better understand them. Thanks for your time, enjoy!

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What are variables?

• Variables are names we assign to storage slots in our computers memory.
• In the picture above, imagine each container is a slot of memory in our computer.
  • The food itself is data sitting in a slot of memory.
  • The labels are variable names we give to that slot of memory.

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How do we use variables?

• We use variables to retrieve data sitting in named storage slots

num1 = 1900   // Save 1900 in storage and name the slot num1
num2 = 121    // Save 121 in storage and name the slot num2
sum(num1 + num2)   // Add data in storage slots num1 & num2

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What are the benefits of using variables?

• Use simple names to evaluate complex expressions
• Rename any storage slot that's holding data
• Replace the data in any storage slot
• Use a single name for similar values in a list of data

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Descriptive Variable Naming (... and why it's important!)

• In my second attempt to oversimplify using a food analogy:
  • Sugar and Salt look the same but they taste completely different
  • It is important that we put them in properly labeled containers or we might get weird tasting food.
  • It is also important that we put data in properly named storage slots or we will get weird expression results / errors.
• Inaccurate variable names will confuse other developers and your future self, which could lead to unexpected results & bugs

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As mundane as variables seem, using them properly is crucial to being a good developer.

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BONUS: Variable Typing

• Some programming languages require us to explicitly define what data type the variables storage slot will hold.

int num1 = 1900   // Variable that only stores integers
str str1 = "A string"   // Variable that only stores strings

• Typing helps productivity by showing us errors when we use a variable incorrectly (Ex: Adding a boolean variable and an integer variable).