Learn how JavaScript is loosely typed, but you can still do some type checking.
- [Instructor] At this point we're aware…of many data types in JavaScript.…We know about numbers, strings, booleans,…objects, arrays, and so forth.…There will be times in JavaScript where you want…to find out what a variable contains,…what type of data it contains.…We're going to look at that in this lesson.…JavaScript doesn't care about data types…to the same extent that some languages do.…In other words, it's loosely typed.…There's a video about strongly versus loosely…typed languages later in this course but for now…just know that JavaScript lets you do what…you want with variables.…
So I've made this variable called thing…and I've put the number 12 into it.…But if I decide later I want to change thing…to a string, that's fine, I can do that.…JavaScript doesn't care at all.…During the execution of a program there…will be many times when you're dealing with uncertainty.…You can get to a variable in a particular portion…of your program and you don't necessarily know…what's in there.…And before you act on that data you might need…
Author
Released
2/5/2019- Using a text editor
- Declaring and assigning variables
- Booleans and the quest for truth
- Working with objects and arrays
- Using operators and control structures
- Iterating with loops
- Objects, references, and functions
- Promises, async, and await
Skill Level Beginner
Duration
Views
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Introduction
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1. Getting Started
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Versions of JavaScript1m 43s
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Additional helpful resources2m 25s
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2. Variables and Types
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3. Objects, Arrays, and More
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Objects3m 21s
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Objects for modeling data2m 20s
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Manipulating objects3m 52s
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Arrays4m 55s
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Manipulating arrays5m 43s
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Readability: Whitespace2m 35s
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Readability: Comments4m 7s
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Regular expressions5m 43s
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4. Operators and Control Structures
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Simple comparisons4m 10s
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Arithmetic operators5m 24s
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Logical operators5m 43s
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Conditionals: If6m 21s
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Conditionals: Switch3m 53s
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Terse ifs4m 59s
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Ternary operator2m 30s
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Type checking5m 30s
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5. Iterating with Loops
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For loops: Sequential6m 9s
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For loops: Enumerative4m 33s
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While loops5m 36s
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6. Functions
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Basic functions2m 40s
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Arguments in functions4m 23s
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More on arguments5m 45s
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Functions are objects4m 18s
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Jargon: Scope in JavaScript1m 55s
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Variable scope in functions3m 20s
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Jargon: Callback functions3m 31s
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7. More Advanced Pieces
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Promises, async, and await3m 26s
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Modern JavaScript tooling3m 21s
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Conclusion
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Next steps3m 38s
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Video: Type checking