WEBVTT 00:00.290 --> 00:03.320 I will call you back again to another video lecture in PHP. 00:03.350 --> 00:10.460 And in this video lecture, let's call ahead and create a simple calculator with user input. 00:16.730 --> 00:24.950 So the aim of this lecture is to be able to implement some calculations using the if statements. 00:24.950 --> 00:29.390 We actually did using some inputs from a user. 00:29.390 --> 00:31.040 So we go to create a form. 00:31.040 --> 00:38.450 And then whatever the user puts inside that form we go ahead and either do an addition a subtraction 00:38.450 --> 00:40.280 division or multiplication. 00:40.280 --> 00:42.890 So we're going to see how that will be done. 00:42.890 --> 00:50.090 So the very first thing we do is to go ahead and create a form and go ahead and close this form. 00:51.560 --> 00:52.010 All right. 00:52.040 --> 00:55.670 Now let's go ahead and uh set action. 00:55.670 --> 01:00.020 And the PHP file is site dot PHP. 01:00.140 --> 01:05.710 And then let's just go ahead and put the method and I'm going to use a post method. 01:05.740 --> 01:07.990 Now that is posts. 01:08.350 --> 01:13.390 So we go ahead and uh put in some numbers. 01:13.390 --> 01:15.490 We're going to accept input from any user. 01:15.490 --> 01:18.130 So go ahead say maybe first number. 01:18.160 --> 01:22.360 And uh next one is second. 01:22.390 --> 01:27.820 Now first none and second none. 01:28.000 --> 01:28.510 All right. 01:28.540 --> 01:29.560 So that is another one. 01:29.560 --> 01:32.800 So in between them you're going to give the operator. 01:32.830 --> 01:39.340 Now let's go ahead and say uh operator okay. 01:39.340 --> 01:41.380 Let's say choose operator. 01:43.570 --> 01:46.210 So it seems that is free to be. 01:46.210 --> 01:48.250 So let's make this to be numbers. 01:48.250 --> 01:51.400 So that is going to also be in a straight line. 01:51.700 --> 01:55.270 So the user will enter the first number. 01:55.270 --> 02:00.280 And then the reason we choose the operator he needs and then choose the second number. 02:00.280 --> 02:03.370 Now the first number that the user inputs. 02:03.370 --> 02:06.040 We are going to create a form for that. 02:06.040 --> 02:14.050 So let's go ahead and say the input type is going to be number because that is what we need. 02:14.050 --> 02:20.500 And then this guy had a name this to be number one. 02:20.620 --> 02:20.920 Right. 02:20.920 --> 02:22.480 So put out to be number one. 02:22.510 --> 02:25.000 Go ahead and close this. 02:25.180 --> 02:28.870 And there it can actually put a break right in here. 02:31.720 --> 02:32.440 All right. 02:32.440 --> 02:35.110 So let's go ahead and drag this a little bit. 02:35.110 --> 02:37.840 And now for the update. 02:37.840 --> 02:42.520 So we go ahead and create an input of text. 02:42.520 --> 02:54.340 So the type is going to be text because I'm going to select either plus minus or division. 02:54.340 --> 02:56.170 So let that be OP. 02:57.220 --> 02:59.560 Let's say OPL are this operator. 03:00.310 --> 03:00.760 Great. 03:00.760 --> 03:03.030 So the next thing is. 03:03.030 --> 03:05.580 So I'll go ahead and copy whatever I have right in here. 03:06.090 --> 03:08.820 Go ahead and copy this and let's go ahead and paste that here. 03:08.850 --> 03:10.740 So for this we'll also put a brick. 03:10.740 --> 03:12.090 So it moves to the next line. 03:12.180 --> 03:16.320 And the this is going to be num2. 03:17.070 --> 03:20.550 Now let's go ahead and save this and refresh this page. 03:20.550 --> 03:24.930 So we have first number set which is an operator. 03:24.960 --> 03:25.980 Second number. 03:26.010 --> 03:28.260 Then we're going to get the output. 03:29.040 --> 03:31.140 Now we have created our form. 03:31.140 --> 03:33.990 We need to go right inside PHP right now. 03:33.990 --> 03:36.810 And then we're going to create some variables. 03:36.810 --> 03:40.290 So we're going to create a variable for Num1 and num2. 03:40.320 --> 03:42.300 So this is variable for Num1. 03:42.300 --> 03:47.040 And then this is let's go ahead and create a second one. 03:47.370 --> 03:50.280 So another variable for num2. 03:50.310 --> 03:57.120 So for number one we're going to get the this we're going to get whatever the user puts in here. 03:57.120 --> 04:07.770 So we go ahead and say no one is equal to um Darci on the score posts because I'm using the post method 04:07.980 --> 04:11.370 and then we go ahead and pass in the name. 04:11.370 --> 04:12.660 So this is the name. 04:12.690 --> 04:14.670 Go ahead and pass in that right there. 04:14.700 --> 04:18.180 So the same thing goes for the second one. 04:18.180 --> 04:21.780 So underscore posts. 04:21.780 --> 04:26.070 And then we pass in this the name. 04:26.100 --> 04:30.240 And always remember to put a semicolon at the end of this is very important. 04:30.270 --> 04:31.140 You always put that. 04:31.140 --> 04:37.980 Now we're going to also create for the operator so that we always choose the operator. 04:37.980 --> 04:41.250 So this is a placeholder to the OP. 04:41.250 --> 04:47.490 Uh, and we go ahead and also use a post for that. 04:47.490 --> 04:53.640 And then we go ahead and put OP uh, because that is the name that we have right in here. 04:53.640 --> 04:55.770 So put semicolon at the end of this. 04:55.770 --> 05:00.570 Now we're going to use if statement we just learned in the previous lectures. 05:00.570 --> 05:08.660 And then go ahead and create It is a key statement and allow users to insert some numbers. 05:08.780 --> 05:09.290 Right. 05:09.290 --> 05:13.190 And then we'll go ahead and choose an operator. 05:13.220 --> 05:19.130 So this decision statement is for the operator because we're going to determine we're going to check 05:19.130 --> 05:25.310 if the user is set an addition subtraction division or multiplication signs. 05:25.340 --> 05:33.560 Now for us to be able to do that I'll go ahead and see if if so the condition is if. 05:34.550 --> 05:37.760 Now the variable operator. 05:37.790 --> 05:45.920 So if the variable OPR with user insights is equal to plus sign, that means that is a division. 05:45.920 --> 05:49.880 So we go ahead and are equal. 05:50.300 --> 05:52.220 So go ahead and equal. 05:55.550 --> 06:02.090 Num1 plus num2. 06:02.120 --> 06:04.250 So put a semicolon at the end. 06:05.120 --> 06:06.560 Now else. 06:07.550 --> 06:13.310 What if it is not because we are looking for a but for conditions. 06:13.340 --> 06:17.720 Addition, subtraction, multiplication and division. 06:18.110 --> 06:19.850 So these are the four things we need. 06:19.850 --> 06:23.390 Any other thing apart from this is an invalid operator. 06:23.390 --> 06:26.600 So we're going to use an else if statement. 06:26.600 --> 06:29.690 So we want to use an else if statement. 06:29.690 --> 06:31.580 So we're going to check for the next operator. 06:31.580 --> 06:35.150 So we're going to say op error. 06:35.990 --> 06:40.370 So if op r is equivalent to let's say minus sign. 06:40.790 --> 06:44.480 So we go ahead and are equal. 06:47.120 --> 06:50.210 So go ahead and are equal. 06:52.310 --> 06:56.150 Now one minus. 06:58.400 --> 07:01.130 Not two for semicolon at the end of this. 07:01.160 --> 07:06.070 Now we won't also check for the next condition because you have two conditions remaining the division 07:06.070 --> 07:07.210 and the multiplication. 07:07.210 --> 07:10.030 So let's go ahead and see if it is multiplied. 07:10.060 --> 07:15.790 So go ahead and say else if else if. 07:17.830 --> 07:19.180 The operator. 07:21.670 --> 07:27.160 The opia operator is equivalent to let's say multiplication. 07:27.160 --> 07:29.470 So it is equivalent to multiplication. 07:29.470 --> 07:39.100 Then we go ahead and uh equal num1 multiply. 07:41.890 --> 07:44.260 Num2 plus semicolon. 07:44.260 --> 07:50.140 At the end of this now we have one more that is remaining. 07:50.170 --> 07:53.410 So we go ahead and uh. 07:53.680 --> 07:54.760 See. 07:58.600 --> 08:09.750 Else if else if the last condition we have Is opia is equal to division. 08:09.750 --> 08:15.060 So if is equal to division we go ahead and equal. 08:17.520 --> 08:21.480 Number one divide. 08:24.150 --> 08:31.830 Number two no one divide number two plus semicolon at the end of this. 08:32.010 --> 08:34.650 So now we have made all the conditions. 08:34.650 --> 08:37.800 So it's remaining and all statement because that is what we. 08:37.830 --> 08:39.810 Are going to use to call the if statement. 08:39.810 --> 08:43.770 And whatever you put outside this whatever you put. 08:43.800 --> 08:46.860 Outside this is an invalid operator. 08:46.890 --> 08:48.780 Now we go ahead and say. 08:51.060 --> 08:51.840 Equal. 08:55.950 --> 08:56.850 Invalid. 08:59.940 --> 09:00.750 Operator. 09:01.320 --> 09:03.900 So semicolon at the end of this. 09:04.110 --> 09:05.640 And that is it for now. 09:05.670 --> 09:07.350 Go ahead and save this. 09:07.620 --> 09:10.890 And then let's go ahead and refresh this and check out. 09:10.890 --> 09:12.630 So we have an error. 09:12.660 --> 09:14.880 It says in line 22. 09:14.910 --> 09:22.470 So line 22 says Unexpected Token LLC. 09:23.130 --> 09:25.500 So now we open this. 09:25.530 --> 09:26.940 We close this right in here. 09:26.940 --> 09:28.320 So go ahead and close this. 09:30.420 --> 09:32.760 So and now we save again. 09:32.760 --> 09:34.380 Let's refresh and check. 09:34.380 --> 09:45.420 And uh it says line one undefined array key number one on the final key number two and undefined Reiki 09:45.450 --> 09:46.260 none. 09:46.650 --> 09:46.860 Uh. 09:46.860 --> 09:48.030 Line 16. 09:48.630 --> 09:51.600 So this guy had an add in maybe two. 09:51.630 --> 09:56.010 I would choose an operator plus, and we add in three. 09:56.040 --> 09:56.850 So we did it. 09:56.850 --> 09:58.680 Put in a submit button. 09:58.710 --> 10:00.930 Now let's add a submit button right in here. 10:00.930 --> 10:03.240 And with that we create the error that is in there. 10:03.240 --> 10:12.650 And then we go ahead and puts Which type is equal to submit and go ahead and close that. 10:12.650 --> 10:13.910 And let's save this. 10:13.910 --> 10:15.380 So refreshing this. 10:15.380 --> 10:17.420 So that is it has gone. 10:17.420 --> 10:22.790 So that error is not a real an error from your code you understand. 10:22.790 --> 10:24.560 So that is not an error from your code. 10:24.560 --> 10:26.540 And that is why you can see we have no error. 10:26.570 --> 10:31.970 Now we have invalid operator right in here because I have not selected anything. 10:31.970 --> 10:39.200 So anything I select, anything you insert in here that is not within plus minus division and multiplication 10:39.200 --> 10:40.070 is invalid. 10:40.100 --> 10:47.780 Now let's go ahead and put in five and let's put plus and let's put seven is equal to 12. 10:47.810 --> 10:48.740 You see that. 10:48.770 --> 10:53.720 Now if we put two I will put division multiplication. 10:53.720 --> 10:55.280 And we'll put in three. 10:55.280 --> 10:57.350 And let's go ahead and push submit. 10:57.350 --> 10:58.580 That is six. 10:58.580 --> 11:08.840 So if you put in four put in division put in Two equal to two. 11:09.200 --> 11:10.100 We see that. 11:11.150 --> 11:12.500 So I hope that is cool. 11:12.500 --> 11:16.580 So that is a way you can be able to actually do this. 11:17.210 --> 11:27.470 So if I should go ahead and say seven and I'm going to say George and put in it, if I put in 7 or 8 11:27.470 --> 11:30.410 and the submit is you can see a valid operator. 11:30.440 --> 11:41.240 Now what if in the case you go ahead and say 6.7 and put in plus and put in three and go ahead and say 11:41.270 --> 11:41.930 equal. 11:41.990 --> 11:44.330 You can see we have an error that is set in here. 11:44.360 --> 11:46.970 Please enter a valid value. 11:47.000 --> 11:51.410 Then two nearest valid values are six and seven. 11:51.410 --> 11:54.170 Because what we are creating this we did. 11:54.290 --> 11:59.030 We only put into account the whole numbers the integer values. 11:59.060 --> 12:07.030 Now if you want to add in decimals you go ahead and go right in here to numbers and put in step and 12:07.360 --> 12:10.450 let it still be equal to 0.1. 12:10.720 --> 12:11.110 All right. 12:11.140 --> 12:14.470 Now, if I should go back here and save this and refresh. 12:14.470 --> 12:16.120 This says submit. 12:16.150 --> 12:21.160 Now I can say 6.7 and let's say plus okay. 12:21.190 --> 12:27.310 If I say minus and let's say two is equal to 4.7. 12:27.310 --> 12:37.420 Now what if I go ahead and say is 6.789 and go ahead and say this is a multiplication or division. 12:37.420 --> 12:39.490 I don't know why I always press that. 12:39.490 --> 12:46.180 So multiplication and not is five and then click on submit. 12:46.300 --> 12:48.850 You can see please enter a valid value. 12:48.880 --> 12:53.890 The two nearest valid values as 6.7 and 6.8. 12:54.370 --> 12:56.290 Now you would be like what? 12:56.320 --> 12:57.160 What is going on? 12:57.190 --> 12:59.440 Now what you need to do is you go right in here. 12:59.440 --> 13:05.590 You can say step is equal to 0.001 to accommodate more of a decimal places. 13:05.620 --> 13:08.320 Go ahead and some of these are fresh. 13:08.350 --> 13:09.340 Let's check it out. 13:10.000 --> 13:11.380 Now I can get in at six. 13:11.410 --> 13:13.720 6.789. 13:13.720 --> 13:17.410 And go ahead and put in multiplication. 13:17.410 --> 13:24.040 And then put in three is equal to 20.367. 13:24.040 --> 13:26.740 So the same thing is applicable to number two. 13:26.770 --> 13:32.320 If you want to add into put into consideration the decimal can go right in here. 13:32.350 --> 13:35.560 Copy this and go right under here and say norm. 13:35.560 --> 13:39.010 And then put in step of three decimal places. 13:39.010 --> 13:48.100 So that is a way to add in uh the the you factor in that is the way you factor in the decimal places, 13:48.100 --> 13:52.960 in your calculator, in your PHP program. 13:52.960 --> 13:54.190 So I hope that is cool. 13:54.190 --> 13:55.270 So pull it down. 13:55.270 --> 13:56.200 Pull down with it. 13:56.230 --> 13:57.760 The code is just very before you. 13:57.790 --> 14:02.950 If you have any question, please use the question and answer section and I'm going to get back to you 14:02.950 --> 14:04.060 as soon as possible. 14:04.090 --> 14:05.110 Thank you so much. 14:05.110 --> 14:08.080 And I'm going to see you in the next video lecture.