var TestString = '+'.repeat(200) + '='.repeat(20000) + '+'.repeat(200); var regexTrim = function(str, ch) { if (ch === ']') ch = '\\]'; else if (ch === '^') ch = '\\^'; else if (ch === '\\') ch = '\\\\'; return str.replace(new RegExp('^[' + ch + ']+|[' + ch + ']+$', 'g'), ''); }; function indexTrim(str, ch) { var start = 0, end = str.length; while(start < end && str[start] === ch) ++start; while(end > start && str[end - 1] === ch) --end; return (start > 0 || end < str.length) ? str.substring(start, end) : str; } function booleanTrim(str, ch) { return str.split(ch).filter(Boolean).join(ch); } function spreadTrim(str, ch) { const first = [...str].findIndex(char => char !== ch); const last = [...str].reverse().findIndex(char => char !== ch); return str.substring(first, str.length - last); } function substringTrim(str, ch) { while(str.charAt(0)==ch) { str = str.substring(1); } while(str.charAt(str.length-1)==ch) { str = str.substring(0,str.length-1); } return str; }