check if a string has balanced brackets (or configurable delimiters)

isBalanced.js

function isBalanced( string, opening_char = "[", closing_char = "]" ) {
	
	let openings = 0;

	for ( let pos = 0; pos < string.length; pos++ ) {

		let char = string[ pos ];

		// if opening, store that info
		if ( char === opening_char ) {
			openings++;
		}
		else if ( char === closing_char ) {

			// if we have no openings, is not balanced
			if ( openings === 0 ) {
				return false;
			}
			// remove the last opening
			else {
				openings--;
			}
		}

	}

	// if we have any leftover openings, is not balanced
	if ( openings !== 0 ) {
		return false;
	}

	return true;

}