WEBVTT 00:01.520 --> 00:07.240 Pointers provide a lot of flexibility, but this flexibility comes at safety cost. 00:07.250 --> 00:13.580 So if you don't need the flexibility or receipt ability a nullptr. 00:13.710 --> 00:16.880 References are the go to reference type. 00:16.880 --> 00:21.330 So let's drive home to the point that references cannot be reseated. 00:21.350 --> 00:28.550 So here we're going to initialize an integer reference in this lecture and then we will attempt to reseat 00:28.580 --> 00:31.070 it with the new value. 00:31.610 --> 00:35.360 So as always, we have to use the include. 00:35.390 --> 00:40.730 We will use the library, CS uh, studio here and. 00:41.830 --> 00:46.930 Then we're going to create the original variable and assign to 100. 00:47.110 --> 00:56.350 And if you like, have the problem understanding this code, which as I as I always do, I will explain 00:56.350 --> 00:58.300 after when we write the code. 00:58.480 --> 01:09.160 This is ampersand here, original href here, and we're going to assign it to original original here. 01:09.250 --> 01:11.530 And then we will print that. 01:12.250 --> 01:17.310 So remember, we included this the system library. 01:17.320 --> 01:17.980 That's why. 01:18.010 --> 01:21.130 Because we need to use the printf here. 01:21.280 --> 01:22.420 So. 01:26.490 --> 01:27.150 Here. 01:27.180 --> 01:35.730 As you can see here, we do no longer have the function print F, So that's why we included this print, 01:36.150 --> 01:39.660 this studio, um, library here. 01:39.660 --> 01:41.580 So include it again. 01:43.280 --> 01:43.850 Here. 01:43.850 --> 01:47.270 And as you can see, our printf function returns. 01:47.310 --> 01:49.880 So original here? 01:50.720 --> 01:51.260 Yes. 01:52.160 --> 01:53.470 Original here. 01:53.480 --> 01:53.930 The. 01:57.190 --> 02:01.540 And then we're going to print the original value. 02:01.540 --> 02:06.010 And then let's add another print function here and reference. 02:06.870 --> 02:07.290 Here. 02:12.770 --> 02:13.400 Here. 02:15.680 --> 02:16.670 And. 02:19.460 --> 02:22.540 Original dot reference, as you can see here. 02:22.550 --> 02:25.460 And then we're going to create a new value. 02:25.880 --> 02:28.580 Named new value and assign it to 100. 02:30.490 --> 02:36.240 Integer new value is assigned to 200 and original ref. 02:36.250 --> 02:38.350 We will use this original ref here. 02:38.800 --> 02:42.850 Original ref equals new value. 02:42.940 --> 02:46.590 And then we're going to print again this here. 02:46.600 --> 02:52.540 As you can see here, we're going to firstly, we're going to print the original, then new value. 02:52.540 --> 02:56.590 And then lastly, we're going to print the reference variable here. 02:56.620 --> 02:58.780 The first is original here. 03:02.540 --> 03:03.560 We three. 03:04.990 --> 03:07.150 We're going to pass this original here. 03:09.350 --> 03:12.140 Then we're going to print the original ref. 03:17.010 --> 03:18.420 Or new value here. 03:32.350 --> 03:34.150 And lastly, we're going to print the reference. 03:35.970 --> 03:36.300 Here. 03:38.790 --> 03:39.390 Reference. 03:39.390 --> 03:40.020 So. 03:40.020 --> 03:41.100 And then we're going to. 03:41.640 --> 03:43.650 Here, let me write it. 03:43.710 --> 03:44.190 Okay. 03:44.520 --> 03:45.960 Ref Original referee. 03:46.290 --> 03:47.790 So let's run our code. 03:51.330 --> 03:53.220 And that's our output here. 03:53.220 --> 04:05.250 So now the program here initializes initializes an integer called original and 200 here, as you can 04:05.250 --> 04:05.520 see. 04:05.640 --> 04:12.510 Then it declares a reference to original called original ref here, as you can see here. 04:12.510 --> 04:21.120 So from this point on, the original ref will always refer to original here, as you can see here. 04:21.120 --> 04:28.200 So this is illustrated by printing the value of original here. 04:30.420 --> 04:33.690 And the value of refer to type original ref. 04:34.230 --> 04:37.800 So as you can see here, we got the 100 here. 04:38.010 --> 04:48.420 Then you initialize another integer called new value to 200 and then assign original to it. 04:49.230 --> 04:50.400 As you can see here. 04:50.700 --> 04:51.630 So. 04:53.060 --> 04:53.870 Here. 04:54.530 --> 05:00.530 Read it carefully that the assignment here doesn't recede. 05:00.560 --> 05:01.760 Original ref. 05:01.940 --> 05:05.510 So that is points to new value. 05:05.810 --> 05:12.320 Rather, it assigns the value of new value to the object it points to. 05:12.350 --> 05:14.280 That is the original. 05:14.300 --> 05:24.290 So the upshot is that all of these variables original original ref and new value evaluate to 100 after 05:24.290 --> 05:25.640 this code here.