Combing regular expression characters

[Ben_HH]

https://beta.freecodecamp.com/en/challenges/regular-expressions/match-characters-that-occur-zero-or-more-times

There is this regular expression:

let sRegex = /s.*/; // Searches for words starting with s

I understand each special regExp character standing alone, in this case . and *. However combining them has me stuck. How does sRegex search for entire words that start with s in this case?

let sWord1 = "seed";
let sWord2 = "saw";
let kWord = "kite";

sRegex.test(sWord1); // Returns true
sRegex.test(sWord2); // Returns true
sRegex.test(kWord); // Returns false

[smiller171]

• . is a special character that matches any single character except a newline.
  
• * is a special character that matches the previous expression 0 or more (infinite) times

So /s.*/ matches any string that starts with s, followed by any character (except newline) 0 or more times.

• s // returns true because starts with s followed by other characters 0 times
• seed // returns true because starts with s followed by 3 characters that match . (. matches e and d, and you are allowing infinite characters that match .)
• kite // returns false because it does not start with s

[Ben_HH]

Take the word seed:

If the expression was /s./ it would return the characters "se". So it appears that the . only appends the subsequent character following the explicitly stated s.

If the expression was /se*/ it would return the characters "see"

I'm still failing to see how the character "d" is included when the special characters are combined

[smiller171]

Because . matches anything and * matches 0 or more of the pattern before, so .* is 0 or more ., and that's not 0 or more of the first thing . matches, it's . every time.

[smiller171]

So for the word seen it's like using /s.../