Free Printable Hackharbor 3.0 Day 4:Tech

Worksheets

Name

Class

Date

Which statement below accurately describes JavaScriptʼs typing system?

JavaScript requires explicit data type declaration for every variable

JavaScript is statically typed like C

JavaScript is dynamically typed and infers the data type at runtime

JavaScript cannot change a variableʼs type once assigned

Whatʼs the difference between null and undefined in JavaScript?

Both mean the same: variable has no value

null means variable is declared but empty, undefined means variable does not exist

undefined means variable is declared but not assigned; null is an assigned “empty” value

None, they are interchangeable

What will happen if you omit semicolons at the end of statements in JavaScript?

JavaScript inserts them automatically in most cases

The script will never run

It causes syntax errors every time

The browser ignores the whole script

Which one of these is the recommended way to attach multiple event listeners to the same button?

Use multiple onclick attributes on button element

Use inline onclick plus .addEventListener()

Use .addEventListener() multiple times on the button element

Overwrite the buttonʼs .onclick property multiple times

Why did JavaScript go to therapy?

Because it had too many types of issues: null, undefined, and mixed feelings about == vs ===!

To learn Python

Because it couldnʼt decide if it wanted to be static or dynamic

It wanted a break from browsers

If you place a