JS: String.prototype.search

str.search(regex_or_str)

• Return the index of first char of matched string.
• If no match, returns -1.
• If argument is string, it is converted to regex by RegExp

// find digit
console.log("a 99 b".search(/\d/) === 2);
// true

// using string as arg
console.log("a 99 b".search("\\d") === 2);
// true

// not found
console.log("a 99 b".search("ttt") === -1);
// true