Php program code for removing spaces from variables

In PHP, we need to clear spaces in the variable. First, let's look at the following method:

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$ Arr = explode ("", $ ); Foreach ($ arr as $ value) { $ Result. = $ value; } Echo "removed blank:". $ result;

Another method is as follows:

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$ Str = str_replace ("", "", $ str ); $ Str = str_replace (chr (32), "", $ str)

The preceding method can only process English spaces.
The following method can process Chinese characters with only spaces. However, if encoding is specified on the page, garbled characters may occur.

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$ Str = str_replace (chr (32), "", $ str ); $ Str = str_replace (chr (161), "", $ str );

For the UTF-8 for the page is, after the Chinese space is submitted into the chr (227), the original should be chr (161)

The following tests show that using the trim (), ltrim (), rtrim () functions can also achieve our desired results.

The syntax and usage of trim () system functions are described as follows:

String trim (string $ str [, string $ charlist])
The trim () function removes spaces (not just spaces) between the start position and the end position of the input string ).
If the second parameter is not set, the trim () function removes the following characters:
"": Space;
"\ T": tab;
"\ N": Line break;
"\ R": Carriage return;
"\ 0 & Prime;: Null character;
"\ X0B": Vertical Tab;
If the second parameter is set, the trim () function removes only the character set in the second parameter, and does not remove the default character set above.

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1 <? Php 2 $ str = "hello world "; 3 $ str_trim = trim ($ str ); 4 echo "$ str <br/> $ str_trim "; 5?> Let's take a look at the output: Hello world

How is the same? Why does the space in the first line disappear. Haha. Let's take a look at the HTML code of the webpage:
Hello world
The space is displayed! The space is not displayed because the browser automatically displays spaces without division.

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1 <? Php 2 $ str = "Left hello world Right "; 3 $ str_trim = trim ($ str, "eftL "); 4 echo "$ str <br/> $ str_trim "; 5?> Output result: Left hello world Right

We will remove all the characters related to the eftL on the left. You may have noticed that the "t" in the Right on the Right is also in the second parameter. Why is it not removed. The last character of $ str is actually a space. Because Spaces (rightmost) are not removed (can be seen in HTML), "t" (penultimate on the right) will not be processed. This also indicates that the second parameter of the function will overwrite the default character set of trim.
Finally, let's talk about the ltrim () and rtrim () functions:
The ltrim () function only processes the left side of the string;
The rtrim () function only processes the right side of the string;

Use regular expressions to replace and improve functions

Php removes spaces at the beginning and end of the string (including the full angle)

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<? $ Str = "www.www.www.111cn.net "; $ Str = mb_ereg_replace ('^ (|) +', '', $ str ); $ Str = mb_ereg_replace ('(|) + $', '', $ str ); Echo mb_ereg_replace (''," \ n ", $ str ); ?>