js中正则特殊符号(国外英文资料).docVIP

js中正则特殊符号(国外英文资料) The JavaScript regular expression notation is detailed Tag: the JavaScript regular symbol expression is created by: 2010-04-2210:53:44 The first way: Var reg = / pattern /; The second way: Var reg = new RegExp ( pattern ); A profile of the exec method for regular expressions Grammar: Reg. The exec (STR); The STR is the target string to execute the regular expression. Such as: Script type = text/Java script , var reg = / test /; Var STR = testString; Var result = reg. exec (STR); Alert (result); / script The test will be output because the regular expression reg matches the test substring in STR ( testString ) and returns it. We use the following functions to do the regular exercise: Function execReg (STR) {var result = reg.exec (STR); Alert (result); } The function accepts a regular expression parameter, reg, and a target string parameter, STR, and then performs the matching result of the regular expression with the string. Using this function test the example above is: script type = text/Java script, function execReg (STR) {var result = reg. Exec (STR). Alert (result); } var reg = / test /; Var STR = testString; ExecReg (reg, STR); / script The above example USES a regular test to match the test in a string, which is boring, and the same task is done using the indexOf method. With regular, it is natural to do more powerful things: A piece of two pieces of three or four pieces, which fell out of all the regular features The above subtitle translates to regular {1}, {2}, {3, 4}, {1}. C {n} {1} means one. / c {1} / can only match a c. / c {2} / will match two consecutive cs. By analogy, / c {n} / will match n consecutive c. Look at the following examples: Reg = / c {1} /; STR = cainiao; ExecReg (reg, STR); Returns the result c Reg = / c {2} /; STR = cainiao; ExecReg (reg, STR); The return result is null, indicating that no match is successful. Reg = / c {2} /; STR = ccVC jello. ExecReg (reg, STR); Returns the results cc. {c m, n} C {3, 4} mean