On windows, holding down left alt and typing in a special numerical code will type a special character.
Does holding the option key and using the numerical row work the same way on High Sierra? Or am I stuck with looking up said special characters and copying and pasting them?
iMac Pro
Some general information, in addition to the Keyboard Viewer and its virtual keyboard previously linked...
How to use emoji, accents, and symbols on your Mac - Apple Support
Keyboard shortcuts for Terminal on Mac - Apple Support
The Keyboard selection and the Keyboard Viewer can also be enabled on the menu bar, off to the right. > Keyboard > Input Sources > Show input menu in menu bar. That allows a path to select different keyboards, and to access the Keyboard Viewer; the virtual keyboard.
⌘^␠(command control space) launches the Character Viewer input selector, and which is a quick way to get to a character selector, and to frequently-used characters. The Character Viewer is rather different from the Keyboard Viewer linked earlier.
Or enable the Unicode Hex Input keyboard (> Keyboard > Input Sources > + > Other > Unicode Hex Input > Add), and get the macOS analog of what you seek. ⌘⇧␠ (command-shift-space) selects an alternate input keyboard—that can be remapped—and then the ⌥/Alt/Option Unicode hex input works as you wish, whenever the Unicode Hex Input keyboard is selected. (See image below, from High Sierra. In the example, two existing keyboards are present and configured, and a third is being added.)
In the default keyboard, there's stuff already mapped to the ⌥/Alt/Option key. ⌥⇧K gets , for instance. Switching to the Unicode Hex Input keyboard means not having to un-do all that mapping.
Alt keys
