It should be noted that next() sends an implicit null into the generator to ensure that code execution isn't blocked if the generator is expecting a value to be sent into it and the code doesn't execute any send()
(PHP 5 >= 5.5.0, PHP 7)
Generator::next — 生成器继续执行
此函数没有参数。
没有返回值。
It should be noted that next() sends an implicit null into the generator to ensure that code execution isn't blocked if the generator is expecting a value to be sent into it and the code doesn't execute any send()