Web Scraping Stock Prices Using Regular Expressions … Look-Behind & Look-Ahead Methods

let STOCKS_NASDAQ = ['NVDA','TSLA', 'AMZN'];

async function func_lookupStock(stock){
const URL = `https://www.google.com/finance/quote/${stock}:NASDAQ`;
let response = await fetch(URL);
let HTML = await response.text();

let lookB = '(?❮=data-last-price=\")';
let lookA = '(?=\" data-last-normal-market-timestamp)';
let priceMatch = HTML.match(lookB + '.*?' + lookA)[0];
return priceMatch
}

// Main Function
(async() =❯ {
let arrayPromise1 = STOCKS_NASDAQ.map(stock =❯ func_lookupStock(stock));
let arr_stock = await Promise.all(arrayPromise1);
console.log(arr_stock);
})()

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Practice / Explaination (https://regex101.com)
Regular Expression (RE) Examples:
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. any 1 character
.? any 0 or 1 character
[0-9] any 1 number character
[a-Z] any 1 letter character
[^3] any 1 character except 3
^123$ newline starts with 1, then 2, then newline ends with 3

.{3-4} any 3 to 4 characters
.* any 0 or more characters
.+ any 1 or more characters
.*? any 0 or more non-greedy characters
(dog | cat) either dog or cat group characters

\ escape character for ( " . \ ^ $ * + ? ... more )

(?❮=123) lookbehind for 123 group characters
(?=678) lookahead for 678 group characters
(?❮=123)..(?=678) will return 45 for (example data: 12345678)

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