【php】Using the "__toString()" method

We have mentioned before that the method of declaring the method name starting with "--" in the class (provided by PHP),

are all methods that are automatically called and executed under different circumstances at a certain time, the "__toString()" method It is also automatically called.

It is automatically called when the object reference is directly output. Earlier we said that the object reference is a pointer.

For example: "$p=new Person()", $p is a Quote,

We cannot use echo to directly output $p, which will output an error like "Catchable fatal error: Object of class Person could not be converted to string",

If you define "__toString()" in the class method, when directly outputting the object reference, no error will be generated,

Instead, the "__toString()" method is automatically called, and the characters returned in the "__toString()" method are output,

So "__toString() "The method must have a return value (return statement).

	function __toString(){
			/* 加到session中， 存储下标为code */
			$_SESSION["code"] = strtoupper($this->checkCode);  //随机产生的字符内容存在session里面
			$this->outImg();             					
			return '';
		}

The above introduces the use of [php] "__toString()" method, including the relevant content. I hope it will be helpful to friends who are interested in PHP tutorials.