Extract a substring using substr() and substring():
// Get the last character. last_char = str.substr(str.length-1, 1); // Get a substring starting from the beginning to the first underscore (excluding). substr = str.substring(0, str.indexOf('_', 0)); // Get a substring starting from the beginning to the last underscore (excluding).<br /> substr = str.substring(0, str.lastIndexOf('_')); // Get a substring starting from the last underscore (excluding) to the end. substr = str.substring(str.lastIndexOf('_')+1); // Get substring starting from n to the end. substr = str.substring(n); // Get a substring starting from the first '/' (including) to the end. substr = str.substring(str.indexOf('/', 0)); // Get a substring from the beginning to the one-before-last character (including). substr = str.substring(0, str.length-1);
Common operations on strings:
// Get the string in lowercase and uppercase. str_lower = str.toLowerCase(); str_upper = str.toUpperCase(); // Replace all occurences of \n with <br /> str = str.replace(/\n/g, '<br />'); // Remove a certain character (e.g. '%'): str = str.replace(/%/g, ''); // Get a character from an ASCII code. str = String.fromCharCode(255); // Capitalize the first character. str = str.charAt(0).toUpperCase() + str.substr(1); // Trim spaces. str = str.replace(/^\s*/, ''); str = str.replace(/\s*$/, '');
Return an index of the first non-whitespace character in a string:
function getFirstNonWhitespaceIndex(str) { var whitespace = " \t\n\r"; if ((str == null) || (str.length == 0)) return -1; // Search through string's characters one by one // until a non-whitespace character is found. for (var i=0; i<str.length; i++) { var c = str.charAt(i); if (whitespace.indexOf(c) == -1) return i; } return -1; }