JavaScript variables can hold numbers or strings, which can make it difficult for beginner programmers to grasp. In this tutorial, Simon teaches how to clean up with string concatenation, and how to use and understand the built-in functions of JavaScript to ensure the variables in your code are correctly recognized.
So JavaScript is a weakly typed language.…Meaning our variables can hold numbers, they can hold strings, they can hold…Booleans, but JavaScript still cares, it knows the difference, and it treats…those values differently.…Let me show you an example.…If I create two variables, foo and bar, and I give them numeric values,…the number 5 without double quotes, then I call alert adding them together.…I'm using the addition operator, the plus sign.…What I'll get will be the number 10.…
It understands these are numbers.…It adds them together.…If on the other hand, I create these variables with the digit 5, but inside…double quotes as a string and then I use exactly the same code, I'm using the…addition operator to add them together,…what's going to happen is concatenation, not addition.…They are going to put them beside each other and what will be output is 55.…This is a behavior you do occasionally want to have happen even when the values…in your strings are what we think of as numeric.…
So you're working with area codes and phone numbers.…
Author
Simon Allardice
Released
9/22/2011Finally, the course compares how code is written in several different languages, the libraries and frameworks that have grown around them, and the reasons to choose each one.
- Writing source code
- Understanding compiled and interpreted languages
- Requesting input
- Working with numbers, characters, strings, and operators
- Writing conditional code
- Making the code modular
- Writing loops
- Finding patterns in strings
- Working with arrays and collections
- Adopting a programming style
- Reading and writing to various locations
- Debugging
- Managing memory usage
- Learning about other languages
Skill Level Beginner
Duration
Views
Q: Using TextEdit with Mac OS 10.9 Mavericks?
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Introduction
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Welcome1m 13s
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1. Programming Basics
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What is programming?5m 45s
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Writing source code5m 34s
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2. Core Programming Syntax
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Why JavaScript?4m 45s
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Requesting input4m 50s
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3. Variables and Data Types
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Working with numbers5m 4s
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Working with operators4m 47s
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Properly using white space6m 46s
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4. Writing Conditional Code
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Setting comparison operators6m 59s
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5. Modular Code
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Breaking your code apart4m 1s
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Understanding variable scope2m 23s
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6. Iteration: Writing Loops
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Introduction to iteration4m 28s
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Writing a while statement5m 24s
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Creating a for loop3m 39s
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7. More About Strings
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8. Collections
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Working with arrays5m 46s
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Array behavior5m 29s
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9. Programming Style
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Programming style5m 55s
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Writing pseudocode4m 55s
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10. Input and Output
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Event driven programming7m 47s
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Introduction to file I/O6m 51s
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11. When Things Go Wrong
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Introduction to debugging5m 57s
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Understanding error messages3m 21s
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Using debuggers8m 2s
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12. Introduction to Object Orientation
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Using classes and objects6m 28s
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13. Advanced Topics
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14. Exploring the Languages
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Introduction to languages1m 42s
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C-based languages4m 40s
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The Java world3m 13s
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Ruby3m 4s
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Python2m 56s
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Objective-C4m 3s
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Libraries and frameworks3m 25s
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Conclusion
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Where to go from here1m 2s
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Video: Cleaning up with string concatenation