在比较运算符（>、<、>=、<=、==、===、!=、<>、!==）、赋值运算符（=）、数学运算符（+、-、*、/、%）、位运算符（&、|、^、~、>>、<<）、逻辑运算符（!、&&、||）、冒号(:)、问号（?）、字符串连接运算符（.）、字符串连接赋值运算符(.=）前后，以及左括号（(）前（函数调用例外）、逗号（,）后请使用空格进行间隔。 例如: /* These are all wrong. */ $i=0; /* These are all right. */ $i = 0; /* These are all wrong. */ if($i<7) ... /* These are all right. */ if ($i < 7) ... /* These are all wrong. */ if ( ($i < 7)&&($j > 8) ) ... /* These are all right. */ if (($i < 7) && ($j > 8)) ... /* These are all wrong. */ do_stuff($i,"foo",$b); /* These are all right. */ do_stuff($i, "foo", $b); /* These are all wrong. */ for($i=0; $i<$size; $i++) ... /* These are all right. */ for ($i = 0;$i < $size;$i++) ... /* These are all wrong. */ $i=($j < $size)?0:1; /* These are all rightg. */ $i = ($j < $size) ? 0 : 1;