Checks if a given string starts with a substring of another string

Starts with substring in Javascript.js

// Changed the loop to start from the end of the word string and iterate backwards.
// This allows us to avoid unnecessary slicing operations.
//Used substring instead of slice since we only need to get the substring starting from i to the end.

/**
 * Finds the longest substring of the word that is a prefix of the text.
 *
 * @param {string} text - The text to search for the substring.
 * @param {string} word - The word to find the substring from.
 * @return {string|undefined} The longest substring that is a prefix of the text, or undefined if no such substring exists.
 */
function startsWithSubstring(text, word) {
    for (let i = word.length - 1; i >= 0; i--) {
        const substr = word.substring(i)
        if (text.startsWith(substr)) return substr
    }
    return undefined
}
startsWithSubstring("/>Lorem ipsum dolor sit amet", "<br />") //= `/>`