PHP Introductory Tutorial String function Learning Notes (1/3)

The PHP language is a powerful embedded HTML scripting language, and its ease of use allows many programmers to choose between them. PHP to determine the inclusion of a string, you can use PHP's built-in function Strstr,strpos,stristr direct judgment. You can also write a judgment function by using the function of explode.

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The following is a detailed description of how the PHP decision string is contained:
1. Strstr: Returns a string from the start of the judged character to the end, and if there is no return value, does not contain

The code is as follows:

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< PHP /* As an example in the manual * * $email = ' user@example.com '; $domain = Strstr ($email, ' @ '); Echo $domain; Prints @example. com ?>

2. STRISTR: It is exactly the same as strstr. The only difference is that STRISTR is case-insensitive.

3. Strpos: Returns a Boolean value. False and true are not to be said. Use "= = =" to judge. Strpos is faster than two functions in execution speed, and Strpos has a parameter that specifies the location of the decision, but the default is null. The disadvantage is that the Chinese support is not good.

The PHP judgment string contains the following code:

The code is as follows	Copy Code
$STR = ' abc '; $needle = ' a '; $pos = Strpos ($str, $needle);

4. Use Explode to judge

The PHP judgment string contains the following code:

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function Checkstr ($STR) { $needle = "a";//decide whether to include a character $tmparray = Explode ($needle, $str); if (count ($tmparray) >1) { return true; } else{ return false; } }

The above is the specific code example that the PHP judgment string contains.

Remove the white space character at the end of the string or any character-trim-returns the removed string

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/* Format: Trim (string, ' special character to be removed can be multiple ') * * $str =trim (' admin '); Echo $str; Admin has no spaces on either side echo $str =trim (' admin ******** ', ' * '); Admin echo strlen ($STR); 5 through the length of the word have has not been removed

Remove the white-space character or any character on the right side of the string-RTrim-Returns the removed string

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/* Format: RTrim (String, ' special character to be removed can be multiple ') * * $str =rtrim (' admin '); Echo $str; No spaces on the right side of ' admin ' echo $str =rtrim (' admin ******** ', ' * '); Admin echo strlen ($STR); 10 through the length of the word have has not been removed

Remove the white space character or any character to the right of the string-Chop-Chop is RTrim alias

The code is as follows	Copy Code
/* Format: Chop (string, ' special character to be removed can be multiple ') * * $str =chop (' admin '); Echo $str; No spaces on the right side of ' admin ' echo $str =chop (' admin ******** ', ' * '); Admin echo strlen ($STR); 10 through the length of the word have has not been removed

Remove whitespace or any character from the left of the string-LTrim-Returns the removed string

The code is as follows	Copy Code
/* Format: LTrim (String, ' special character to be removed can be multiple ') * * $str =rtrim (' admin '); Echo $str; No spaces on the right side of ' admin ' echo $str =ltrim (' admin ******** ', ' * '); ' Admin ******** ' echo strlen ($STR); 14 through the length of the word have has not been removed

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