Return the position of the first occurrence of the string passed as parameter in the current string.
It returns the index of the start of the occurrence, or -1 if no occurrence is found.
You can search using a regular expression (and in reality, even if you pass a string, that’s internally and transparently used as a regular expression too).
More js tutorials:
- The Object getOwnPropertySymbols() method
- The Object create() method
- What's the difference between a method and a function?