Initial data commit

Task/Regular-expressions/Objective-C/regular-expressions-1.m

@@ -0,0 +1,9 @@
+NSString *str = @"I am a string";
+NSString *regex = @".*string$";
+
+// Note: the MATCHES operator matches the entire string, necessitating the ".*"
+NSPredicate *pred = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", regex];
+
+if ([pred evaluateWithObject:str]) {
+    NSLog(@"ends with 'string'");
+}

Task/Regular-expressions/Objective-C/regular-expressions-2.m

@@ -0,0 +1,4 @@
+NSString *str = @"I am a string";
+if ([str rangeOfString:@"string$" options:NSRegularExpressionSearch].location != NSNotFound) {
+    NSLog(@"Ends with 'string'");
+}

Task/Regular-expressions/Objective-C/regular-expressions-3.m

@@ -0,0 +1,6 @@
+NSString *orig = @"I am the original string";
+NSString *result = [orig stringByReplacingOccurrencesOfString:@"original"
+                                                   withString:@"modified"
+                                                      options:NSRegularExpressionSearch
+                                                        range:NSMakeRange(0, [orig length])];
+NSLog(@"%@", result);

Task/Regular-expressions/Objective-C/regular-expressions-4.m

@@ -0,0 +1,10 @@
+NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"string$"
+                                                                       options:0
+                                                                         error:NULL];
+NSString *str = @"I am a string";
+if ([regex rangeOfFirstMatchInString:str
+                             options:0
+                               range:NSMakeRange(0, [str length])
+     ].location != NSNotFound) {
+    NSLog(@"Ends with 'string'");
+}

Task/Regular-expressions/Objective-C/regular-expressions-5.m

@@ -0,0 +1,7 @@
+for (NSTextCheckingResult *match in [regex matchesInString:str
+                                                   options:0
+                                                     range:NSMakeRange(0, [str length])
+                                     ]) {
+    // match.range gives the range of the whole match
+    // [match rangeAtIndex:i] gives the range of the i'th capture group (starting from 1)
+}

Task/Regular-expressions/Objective-C/regular-expressions-6.m

@@ -0,0 +1,9 @@
+NSString *orig = @"I am the original string";
+NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"original"
+                                                                       options:0
+                                                                         error:NULL];
+NSString *result = [regex stringByReplacingMatchesInString:orig
+                                                   options:0
+                                                     range:NSMakeRange(0, [orig length])
+                                              withTemplate:@"modified"];
+NSLog(@"%@", result);