PHP type conversion problems

I wrote the following code for PHP type conversion: & lt ;? Php & nbsp; $ a & nbsp; = & nbsp; ''; & nbsp; & nbsp; // & nbsp; $ a & nbsp; = & nb PHP type conversion problem
I wrote the following code:

 $ A = ''; // $ a = ""
Var_dump ($ a); // string (0 )""
Echo"
";
$ B = 1;
Var_dump ($ B); // int (1)
Echo"
";
$ A + = $ B;
Var_dump ($ a); // int (1). This is the problem. how can we make variable a of the string type?
Exit;

Excuse me:
What are the default transformation rules for PHP variables?
What is the most commonly used forced conversion function in development?
Php string
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Var_dump (string) $ );
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$ A + = $ B
Yes
$ A = $ a + $ B
Since you are performing arithmetic operations, the result is of course a numerical value rather than a string.

$ A. = $ B
Is the string
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$ A = strval ($ );
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$ A = intval ($ a); $ a = int ($ a), both of which are forcibly converted to an integer.
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Var_dump (string) $ a); // method 1
Var_dump (strval ($ a); // method 2
Settype ($ a, "string"); // method 3
Var_dump ($ );

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For more information, see The php Manual!
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For example:
$ A = '1 ';
$ B = '2'; // $ B = 2; the same result is true for int.

$ A + = $ B; // enter 3
$ A. = $ B; // enter 12

It depends on what operations LZ is going to perform.