Getting Started with JavaScript in Chrome Console & Snippets
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Open a new tab in Chrome.
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Go to Menu → View → Developer → JavaScript Console or ( Ctrl + Shift + j ).
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The Console allows you to write JavaScript code directly and run it instantly by pressing Enter.
Example:
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Press Enter and a pop-up will appear showing “Hello”.
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Click OK to close the pop-up.
2️⃣ Writing Multi-Line Code
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If you want multiple alerts one after another:
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To write multi-line code in the console, hold Shift + Enter to go to the next line without running the previous one.
3️⃣ Using Snippets (For Running Larger Scripts)
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Open DevTools → Sources → left corner arrow → Snippets.
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Click + New snippet to create a new JS file (e.g.,
index.js). -
You can write as many lines of code as you want here.
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Once done, click Run to execute the entire script at once.
Example:
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Running this will show a “Hello” pop-up first, then “World”.
4️⃣ Which Instructions Work?
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The browser only recognizes valid JavaScript keywords.
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Example:
say("Hello")will not work becausesayis not a JS keyword. -
Error message:
Uncaught ReferenceError: say is not defined
💡 Meaning: Use only recognized JS commands.
6️⃣ JS Grammar / Syntax
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Semicolon (;) → Marks the end of a statement.
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Quotation marks (" " / ' ') → Denotes a string or text.
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Parentheses ( ) → Used to pass arguments to a function or method.
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Keywords → Commands that tell the browser what to do (e.g.,
alert).
Tip:
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Do not use quotes from Word or Google Docs—they can cause errors.
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Always type code in a proper code editor or Snippet tool for correct symbols.
7️⃣ Stylistic Best Practices
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Double quotes
" "are commonly used; single quotes' 'are used in some cases. -
Consistent code formatting makes your code readable for others.
Summary
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Console → Use for testing small snippets.
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Snippets → Use for multi-line or complete scripts.
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Keywords, semicolons, parentheses, quotes → Fundamental JS syntax.
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Best practices → Keep code readable and uniform.
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