Built in Features of JS

Morning Standup

1. Handling Errors

Key Takeaways

• syntax errors = code not written correctly
• logic errors = code not working correctly
• use dev tools to check for errors
• console.log() is your best friend for diagnosing errors

2. Useful Javascript Objects

Key Takeaways

• DOM methods like document.querySelector() are used by js to interact with html
• use innerText over innerHTML (innerHTML can be dangerous)

DOM Node Activity

• In codepen copy some of the variables that you created yesterday into the javascript box
• use document.querySelector() with the .innerHTML, .textContent, or .innerText methods to render strings to the html page
  • note: all 3 of those do slightly different things

3. The Math Object

• Slides begin on slide 12 of the abovelinked deck

Useful Math methods

• Math.min(): find lowest value in a list
• Math.max(): find highest value in alist
• Math.round(): round a number to nearest integer
• Math.floor(): round down to nearest int
• Math.ceil(): round up to the nearest int
• Math.sqrt(): return square root of a number
• Math.pow(): return value of x to power of y
• Math.random(): return a random number between 0 and 1

Numbers and Math in JS

Key Takeaways

Operators

• addition +
• subtraction -
• multiplication *
• division /
• remainder %
• exponent **
• increment ++
• decrement --

Order of Operations

1. Brackets
2. Exponents
3. Divide/Multiply
4. Add/Subtract

Practicum Discussion with Terry @ 12:30

Terry will join us and talk about the practicums with us. Afterwards, we will have open lab time