Difference between revisions of "PHP-and-MySQL/C4/PHP-String-Functions-Part-2/English-timed"
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| − | |Ok | + | |Ok. Back to the second part of the '''String Functions''' tutorial. |
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|00:03 | |00:03 | ||
| − | |I'm going to go through the rest of the functions starting from String Reverse. | + | |I'm going to go through the rest of the functions starting from '''String Reverse'''. |
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|00:08 | |00:08 | ||
| − | |String reverse probably to make sense is s-t-r-rev. | + | |'''String reverse''' probably to make sense is s-t-r-rev. |
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|00:11 | |00:11 | ||
| − | |So what strvev does is it reverses the contents of a string. | + | |So, what '''strvev()''' does is it reverses the contents of a '''string'''. |
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|00:20 | |00:20 | ||
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|00:41 | |00:41 | ||
| − | |I think | + | |I think it's a useful and fun function to use. |
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|00:45 | |00:45 | ||
| − | |Ok - the next set of functions I have grouped together are these: str to lower and str to upper. | + | |Ok - the next set of functions I have grouped together are these: '''str to lower() and '''str to upper()'''. |
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|00:54 | |00:54 | ||
| − | |This basically means string to lower case and string to upper case. | + | |This basically means '''string''' to lower case and '''string''' to upper case. |
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|00:58 | |00:58 | ||
| − | |So if we have our string that equals 'HELLO', I can say echo str to lower and show the value of the string in | + | |So, if we have our '$string' that equals 'HELLO', I can say '''echo''' str to lower and show the value of the $string in here. |
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|01:12 | |01:12 | ||
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|01:15 | |01:15 | ||
| − | |Something similar would happen if I were to say this is 'hello' in | + | |Something similar would happen if I were to say this is 'hello' in small case |
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|01:21 | |01:21 | ||
| − | |And I could say str to upper and that would give me my uppercase version of the string. | + | |And I could say '''str to upper''' and that would give me my uppercase version of the '''string'''. |
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|01:31 | |01:31 | ||
| − | |Now one applicable use of this is when you have user-registration. | + | |Now, one applicable use of this is when you have user-registration. |
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|01:35 | |01:35 | ||
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|01:49 | |01:49 | ||
| − | |The reason is that if I submit a user name - | + | |The reason is that if I submit a user name - let's get rid of this... |
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|01:55 | |01:55 | ||
| − | |Some people actually do this - | + | |Some people actually do this - Let's have a variable user name which equals say 'ALEX'. |
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|02:01 | |02:01 | ||
| − | |And I'll put in these also - uppercase and | + | |And I'll put in these also - uppercase and small case alphabets. |
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|02:07 | |02:07 | ||
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|02:13 | |02:13 | ||
| − | |But if the name is stored as this and you think - well did | + | |But if the name is stored as this and you think - well did I start with a small 'a'? |
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|02:19 | |02:19 | ||
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|02:23 | |02:23 | ||
| − | |So what you can do is say stored user name equals to str to lower of the username. | + | |So, what you can do is say '''$stored user name''' equals to '''str to lower''' of the '''$username'''. |
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|02:29 | |02:29 | ||
| − | |So this would be the stored username in the database | + | |So, this would be the stored username in the database. |
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|02:33 | |02:33 | ||
| − | |Now when they go to login and type in their username in this combination, what we would do is we would convert their typed-in login username to lower case and compare it to the lower case | + | |Now, when they go to login and type in their 'username' in this combination, what we would do is we would convert their typed-in login 'username' to lower case and compare it to the lower case stored version of the 'username'. |
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|02:48 | |02:48 | ||
| − | |So we are taking this and storing a lowercase value inside the database and we are comparing it to a typed-in value which has also been converted to lower case | + | |So, we are taking this and storing a lowercase value inside the database and we are comparing it to a typed-in value which has also been converted to lower case. |
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|02:58 | |02:58 | ||
| − | |Hence we can't go wrong and users are not going to forget their user-names. | + | |Hence, we can't go wrong and users are not going to forget their user-names. |
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|03:07 | |03:07 | ||
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|03:14 | |03:14 | ||
| − | |Ok | + | |Ok. let's go to the next one. |
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|03:22 | |03:22 | ||
| − | |Sub-string count. This would basically count the no. of sub-strings matching to a particular value inside a string. | + | |'''Sub-string count'''. This would basically count the no. of '''sub-strings''' matching to a particular value inside a string. |
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|03:31 | |03:31 | ||
| − | |So here I'll type search equals "My name is alex. What is your name?" | + | |So, here I'll type '''$search''' equals "My name is alex. What is your name?" |
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|03:37 | |03:37 | ||
| − | |So this is our string. | + | |So, this is our '''string'''. |
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|03:41 | |03:41 | ||
| − | |Now if I say we need to echo out the sub-string count... | + | |Now, if I say we need to '''echo''' out the '''sub-string count()'''... |
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|03:49 | |03:49 | ||
| − | |and obviously this stands for sub-string-count, what we want to do is, we want to search our 'search' string... | + | |and obviously this stands for '''sub-string-count''', what we want to do is, we want to search our '$search' string... |
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|04:01 | |04:01 | ||
| − | |and we will specify a string to search for. Now this will return an integer if we put this in a variable called result. | + | |and we will specify a string to search for. Now this will return an integer if we put this in a variable called '''$result'''. |
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|04:20 | |04:20 | ||
| − | |Also the variable result will not return 2 as t-w-o. It will only return 2 as an integer. | + | |Also the variable '''result''' will not return 2 as t-w-o. It will only return 2 as an integer. |
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|04:30 | |04:30 | ||
| − | |So this is quite useful if we are using substring count to search for, lets say, 'alex'. | + | |So, this is quite useful if we are using '''substring count()''' to search for, lets say, 'alex'. |
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|04:36 | |04:36 | ||
| − | |And then it will echo out on its own. | + | |And then it will '''echo''' out on its own. |
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|04:39 | |04:39 | ||
| − | |And if you look through here, you will see there is only one instance of 'alex' | + | |And if you look through here, you will see there is only one instance of 'alex'. |
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|04:44 | |04:44 | ||
| − | |So refresh that - and we should get the number 1. | + | |So, refresh that - and we should get the number 1. |
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|04:46 | |04:46 | ||
| − | |Now if we were to search for 'name' - there's 1 instance of 'name' here and another instance of 'name' here | + | |Now if we were to search for 'name' - there's 1 instance of 'name' here and another instance of 'name' here. |
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|04:52 | |04:52 | ||
| − | |So when we refresh, we should get the value 2. | + | |So, when we refresh, we should get the value 2. |
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|04:55 | |04:55 | ||
| − | |Now there are optional parameters for this | + | |Now there are optional parameters for this which are 'where to start from in a string' and 'where to end in a string'. |
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|05:02 | |05:02 | ||
| − | | | + | |Let's try this out. |
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|05:05 | |05:05 | ||
| − | |So | + | |So let's say- I want to search from after "name", ok? |
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|05:11 | |05:11 | ||
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|05:14 | |05:14 | ||
| − | |So I say search name from 7 onwards. | + | |So, I say search "name" from 7 onwards. |
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|05:19 | |05:19 | ||
| − | |So search name from 7 and it will search in this blue area that I have highlighted here. | + | |So, search "name" from 7 and it will search in this blue area that I have highlighted here. |
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|05:25 | |05:25 | ||
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|05:28 | |05:28 | ||
| − | |So you can specify whereabouts in the string. | + | |So, you can specify whereabouts in the string. |
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|05:30 | |05:30 | ||
| − | |I think you can specify | + | |I think you can specify up to where. |
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|05:33 | |05:33 | ||
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|05:43 | |05:43 | ||
| − | |7 to 17. | + | |7 to 17. Let's check if this works. |
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|05:46 | |05:46 | ||
Revision as of 12:06, 3 June 2015
| Time | Narration |
| 00:00 | Ok. Back to the second part of the String Functions tutorial. |
| 00:03 | I'm going to go through the rest of the functions starting from String Reverse. |
| 00:08 | String reverse probably to make sense is s-t-r-rev. |
| 00:11 | So, what strvev() does is it reverses the contents of a string. |
| 00:20 | So if I were to say 'Hello' and I were to reverse that, it would be "o-l-l-e-H". |
| 00:30 | And it can be useful in some circumstances although you usually wouldn't use this. |
| 00:36 | But you could use this function if you want to specifically reverse a string. |
| 00:41 | I think it's a useful and fun function to use. |
| 00:45 | Ok - the next set of functions I have grouped together are these: str to lower() and str to upper(). |
| 00:54 | This basically means string to lower case and string to upper case. |
| 00:58 | So, if we have our '$string' that equals 'HELLO', I can say echo str to lower and show the value of the $string in here. |
| 01:12 | The 'HELLO' in capitals will now become lowercase. |
| 01:15 | Something similar would happen if I were to say this is 'hello' in small case |
| 01:21 | And I could say str to upper and that would give me my uppercase version of the string. |
| 01:31 | Now, one applicable use of this is when you have user-registration. |
| 01:35 | If you have a website on which users have to register, you should usually always store the user name as a lower string. |
| 01:49 | The reason is that if I submit a user name - let's get rid of this... |
| 01:55 | Some people actually do this - Let's have a variable user name which equals say 'ALEX'. |
| 02:01 | And I'll put in these also - uppercase and small case alphabets. |
| 02:07 | Some people use names like this to make the name look funky and its perfectly okay. |
| 02:13 | But if the name is stored as this and you think - well did I start with a small 'a'? |
| 02:19 | Then I have another pattern for username now. |
| 02:23 | So, what you can do is say $stored user name equals to str to lower of the $username. |
| 02:29 | So, this would be the stored username in the database. |
| 02:33 | Now, when they go to login and type in their 'username' in this combination, what we would do is we would convert their typed-in login 'username' to lower case and compare it to the lower case stored version of the 'username'. |
| 02:48 | So, we are taking this and storing a lowercase value inside the database and we are comparing it to a typed-in value which has also been converted to lower case. |
| 02:58 | Hence, we can't go wrong and users are not going to forget their user-names. |
| 03:07 | You could do the same with passwords. |
| 03:14 | Ok. let's go to the next one. |
| 03:22 | Sub-string count. This would basically count the no. of sub-strings matching to a particular value inside a string. |
| 03:31 | So, here I'll type $search equals "My name is alex. What is your name?" |
| 03:37 | So, this is our string. |
| 03:41 | Now, if I say we need to echo out the sub-string count()... |
| 03:49 | and obviously this stands for sub-string-count, what we want to do is, we want to search our '$search' string... |
| 04:01 | and we will specify a string to search for. Now this will return an integer if we put this in a variable called $result. |
| 04:12 | That's because you can't find any instance of a word which will appear say for 1.2 times. |
| 04:20 | Also the variable result will not return 2 as t-w-o. It will only return 2 as an integer. |
| 04:30 | So, this is quite useful if we are using substring count() to search for, lets say, 'alex'. |
| 04:36 | And then it will echo out on its own. |
| 04:39 | And if you look through here, you will see there is only one instance of 'alex'. |
| 04:44 | So, refresh that - and we should get the number 1. |
| 04:46 | Now if we were to search for 'name' - there's 1 instance of 'name' here and another instance of 'name' here. |
| 04:52 | So, when we refresh, we should get the value 2. |
| 04:55 | Now there are optional parameters for this which are 'where to start from in a string' and 'where to end in a string'. |
| 05:02 | Let's try this out. |
| 05:05 | So let's say- I want to search from after "name", ok? |
| 05:11 | So this is 0 1 2 3 4 5 6. |
| 05:14 | So, I say search "name" from 7 onwards. |
| 05:19 | So, search "name" from 7 and it will search in this blue area that I have highlighted here. |
| 05:25 | It will only return 1 in the result. |
| 05:28 | So, you can specify whereabouts in the string. |
| 05:30 | I think you can specify up to where. |
| 05:33 | So this is 7... 8 9 10 11 12 13 14 15 16. |
| 05:43 | 7 to 17. Let's check if this works. |
| 05:46 | It shows zero. So from 7 to 17 - which is from about here to here - we find zero instances of 'name'. |
| 05:55 | However if we search for 'alex', we will find 1 instance of it. |
| 06:01 | Ok - so that's the substring count function. |
| 06:07 | And now substring replace is similar. |
| 06:12 | Its not the same function but it includes an added bonus where you can replace your string. |
| 06:18 | So the replace tags are - My name is alex and I've added the full-stop on purpose. |
| 06:28 | Our result is equal to substring replace. |
| 06:33 | What do I want to replace in? I want to replace in the variable replace. |
| 06:41 | And I want to replace 'alex' with 'billy'. |
| 06:48 | And this will be from - let me count 0 1 2 3 4 5 7 8 9 10 11 so from 11 until... |
| 07:01 | Its 11 - 0 1 2 3 4 5 6 7 8 9 10 11 - from 11 to 14. |
| 07:14 | So that should replace 'alex' with 'billy'. |
| 07:19 | Replace and refresh. |
| 07:21 | Oh! We didn't echo out result. |
| 07:23 | Lets echo out result and we can refresh this. |
| 07:26 | And it should return my name is billy. |
| 07:30 | This should be 12 and this 15, I think. |
| 07:34 | Or in fact no - it should be 10 and 14. |
| 07:38 | No, not quite right.... We are missing the full-stop. |
| 07:43 | ........ so lets go for 11 and 14. |
| 07:49 | Still missing the full stop and I cant think why. |
| 07:52 | aah! well you get the picture |
| 07:55 | Basically you can replace anything in the string with the starting value and the ending value |
| 07:59 | It will leave it up to you to count through. |
| 08:04 | I'm very tired so I am not able to count. |
| 08:09 | So what we are doing here is we are replacing a particular string with a particular value |
| 08:14 | And here's your starting value and here's your finishing value. |
| 08:17 | That's all in this tutorial. |
| 08:19 | There are many more string functions and I suggest you to search, may be, on 'google'. |
| 08:24 | Search for 'php string functions' and you'll find a lot of interesting functions. |
| 08:28 | If you are looking to do a particular thing there's probably a function available for it. |
| 08:33 | Thanks for watching! This is Osama Butt dubbing for the Spoken Tutorial Project. |
