Ajax return values include carriage return and line breaks and spaces. _ PHP Tutorial

The ajax return values include carriage return, line breaks, and spaces. I recently wrote a page and used jqueryajax to perform the judgment. I just wrote the test, and there was no problem at all. After two days, I found that there was a problem and I couldn't judge it. Later I found that all the responses from alert are written on a page recently. I used jquery ajax to perform the judgment. I just wrote the test and found that there was no problem after two days. Later, we found that some line breaks and spaces are added before the returned values of alert. (Why is there such a problem in the same computer and environment)

Later, I found that some people encountered the same problem on the Internet. This problem exists in jquery $. ajax $. get $. post, or in the XMLHttpRequest method of the original sound. in this way, errors may occur during call and judgment. Look at the example

Ajax code:

The code is as follows:

$. Get ('Ajax. php', {'name': name}, function (data ){
Alert (data );
})

Ajax. php

The code is as follows:

$ Username = $ _ GET ['name'];
Echo $ username;
?>

Obviously, there are line breaks or spaces in front of the string whose name is google. This seriously affects the robustness of the program. I have encountered problems and the judgment of the following programs is not true. Therefore, we need to use the regular expression method to remove it, so we can write

The code is as follows:

$. Get ('Ajax. php', {'name': name}, function (data ){
NewData = data. replace (/\ s/g ,'');
Alert (newData );
})

No need to change ajax. php

Then there is no line break space.

All I see on the Internet are

NewData = data. replace (/rn/g ,'');

However, I found that this regular expression is incorrect for me. I only removed some white space characters in the front. Therefore, I have determined that there should be other white spaces except line breaks and carriage returns, therefore, \ s is used.

/.../G is the attribute of the regular expression, indicating full-text matching, instead of stopping when one is found.

Ajax was used to implement the judgment. the test was just written and there was no problem at all. After two days, it was impossible to judge the problem. Later I found all alert returned results...