two hello world regex examples

Author: shiffman

week2_regex/regex_node/regex_helloworld.js

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+
+// Demonstrates exec() in RegExp
+
+var text = "This is a test of regular expressions.";  
+var regex = /test/;               
+
+// The function exec() executes a search for a match in string.  the result is an array.
+var results = regex.exec(text);
+
+console.log('The match found in the text is: ' + results[0]);
+console.log('And the index where it was found: ' + results.index);
+console.log('And the input text in case you forgot: ' + results.input);
+
+// And again with capturing parentheses, the global flag, and a loop
+text = "Now another test including phone numbers: 212-555-1234 and 917-555-4321 and 646.555.9876.";  
+// Note the use of 'g' for global matches
+regex = /(\d+)[-.]\d+[-.]\d+/g;               
+
+while ((results = regex.exec(text)) != null) {
+  console.log('The full match found in the text is: ' + results[0]);
+  console.log('Group 1 of the match is: ' + results[1]);
+  console.log('And the index where it was found: ' + results.index);
+  // console.log('And the input text in case you forgot: ' + results.input);
+}

week2_regex/regex_node/regex_helloworld1.js

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+
+// Demonstrates match() in String
+
+var text = "This is a test of regular expressions.";  
+var regex = /test/;               
+
+// The function match() executes a search for a match in string.  
+// The result, just like with exec(), is an array.
+var results = text.match(regex);
+
+console.log('The match found in the text is: ' + results[0]);
+console.log('And the index where it was found: ' + results.index);
+console.log('And the input text in case you forgot: ' + results.input);
+
+// Now capturing parentheses and the global flag match() works differently
+// Note we can't actually get group 1 this way
+text = "Now another test including phone numbers: 212-555-1234 and 917-555-4321 and 646.555.9876.";  
+regex = /(\d+)[-.]\d+[-.]\d+/g;               
+
+results = text.match(regex);
+for (var i = 0; i < results.length; i++) {
+  console.log('Match ' + i + ': ' + results[i]);
+}