Test : var ss = new String("String123456EndString"); ss.substring(3,4): i ss.substring(): String123456EndString ss.substring(6,2): ring ss.substring(-6,2): St ss.substr(-6,2): St ss.substr(-1,4): g ss.slice(2, 7): ring1 ss.slice(): String123456EndString Test : var ss = new String("a"); ss.substring(3,4): ss.substring(): a ss.substring(6,2): ss.substring(-6,2): a ss.substr(-6,2): a ss.substr(-1,4): a 3 ss.slice(2, 7): ss.slice(): a 3 Test : var ss = new String("abcdefg123456qweeeeaatt"); ss.replace(): abcdef******3456qweeeeaatt Test : var ss = new String("abcdefg1" + "23456qweeeeaatt"); ss.replace(): abcdef+++++3456qweeeeaatt Test : var ss = new String("abcdefg123456qweeeeaatt"); ss.indexOf("g123"): 6 Test : var ss = new String("abcdefg1" + "23456qweeeeaatt"); ss.indexOf("g123"): 6 Test : var ss = new String("0123456789" + "abcde" + "" + "fghijk" + "lmnoprs"); ss.indexOf("89ab", 4): 8 ss.indexOf("def", 11): 13 ss.indexOf("klm", 15): 20 Test : var ss = new String("0123" + "0123456789" + "" + "01234567" + "234567"); ss.indexOf("0123012"): 0 ss.indexOf("23", 1): 2 ss.indexOf("23", 5): 6 ss.indexOf("23", 10): 16 Test : var ss = new String("0123" + "0123456789" + "" + "hideundefined01234567" + "234567"); ss.indexOf(): 18 Test : var ss = new String("aaccca" + "bbcccb" +"cccc"+"0123" + "0123456789" + "" + "hideundefined01234567" + "234567"); ss.indexOf("6789" + "" + "hideundefined01234567" + "2345", 2): 26 Test : var ss = new String("abcdefg123456qweeeeaatt"); ss.lastIndexOf("g123"): 6 Test : var ss = new String("abcdefg1" + "23456qweeeeaatt"); ss.lastIndexOf("g123"): 6 Test : var ss = new String("0123456789" + "abcde" + "" + "fghijk" + "lmnoprs"); ss.lastIndexOf("89ab", 4): -1 ss.lastIndexOf("def", 18): 13 ss.lastIndexOf("klm", 15): -1 Test : var ss = new String("0123" + "0123456789" + "" + "01234567" + "234567"); ss.lastIndexOf("0123012"): 0 ss.lastIndexOf("23", 1): -1 ss.lastIndexOf("23", 5): 2 ss.lastIndexOf("23", 10): 6 Test : var ss = new String("0123" + "0123456789" + "" + "hideundefined01234567" + "234567"); ss.lastIndexOf(): 18 Test : var ss = new String("String123456EndString"); ss.search("234"): 7 ss.search(/234/): 7 3 Test : var ss = new String("AAAAAAAAAAbbbbbbbbbb"); ss.toLowerCase(): aaaaaaaaaabbbbbbbbbb Test big string ss.toUpperCase(): AAAAAAAAAABBBBBBBBBBAAAAAAAAAABBBBBBBBBBAAAAAAAAAABBBBBBBBBBAAAAAAAAAABBBBBBBBBBAAAAAAAAAABBBBBBBBBBAAAAAAAAAABBBBBBBBBBAAAAAAAAAABBBBBBBBBBAAAAAAAAAABBBBBBBBBBAAAAAAAAAABBBBBBBBBBAAAAAAAAAABBBBBBBBBBAAAAAAAAAABBBBBBBBBBAAAAAAAAAABBBBBBBBBB 3