Method of use

1.text()

let myString = "Hello, World!";
let myRegex = /Hello/;
myString.test(myRegex); 
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Using | matching multiple characters

let petString = "James has a pet cat.";
let petRegex = /dog|cat|bird|fish/;
let result = petRegex.test(petString)
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2.match()

let extractStr = "Extract the word 'coding' from this string.";
let codingRegex = /coding/; 
let result = extractStr.match(codingRegex)
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let twinkleStar = "Twinkle, twinkle, little star";
let starRegex = /Twinkle/gi;
let result = twinkleStar.match(starRegex)
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Add g to the end of the regular expression to indicate full match and I to indicate ignoring case.

Regular expression symbol

Matches any character

let exampleStr = "Let's have fun with regular expressions!";
let unRegex = /.un/; // Change this line
let result = unRegex.test(exampleStr);
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[] Matches one of the characters

let quoteSample = "Beware of bugs in the above code; I have only proved it correct, not tried it.";
let vowelRegex = /[aeiou]/gi;
let result = qutoeSample.match(vowelRegex);
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let quoteSample = "The quick brown fox jumps over the lazy dog.";
let alphabetRegex = /[a-e]/gi; 
let result = quoteSample.match(alphabetRegex); 
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^ Take the character following the reverse mismatch

let quoteSample = "3 blind mice.";
let myRegex = /[^aeiou^0-9]/gi;
let result = quoteSample.match(myRegex);
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Start with ^ match

let firstString = "Ricky is first and can be found.";
let firstRegex = /^Ricky/;
firstRegex.test(firstString); True
let notFirst = "You can't find Ricky now.";
firstRegex.test(notFirst); False
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Use $to match the end

let theEnding = "This is a never ending story";
let storyRegex = /story$/;
storyRegex.test(theEnding); True
let noEnding = "Sometimes a story will have to end";
storyRegex.test(noEnding);  False
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+ Matches one or more characters

let difficultSpelling = "Mississippi";
let myRegex = /s+/gi;
let result = difficultSpelling.match(myRegex);
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* Matches zero or more characters

let chewieQuote = "Aaaaaaaaaaaaaaaarrrgh!";
let chewieRegex = /Aa*/; 
let result = chewieQuote.match(chewieRegex);
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\w corresponds to matching \ a-za-z0-9_ \d as opposed to matching \0-9 \d, which matches non-digits \s matching Spaces {} matching A certain number of characters

let ohStr = "Ohhh no";
let ohRegex = / Oh no / {3, 6}; 
let result = ohRegex.test(ohStr);
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Advance matching (to be completed)