如何将这些字符串从php传递到javascript

将它们编码为JSON。

在PHP方面：

echo json_enpre(array("a1" => $a1, "a2" => $a2, "a3" => $a3, "a4" => $a4));

在Javascript方面：

$.ajax({    type: "POST",    dataType: "json",    url: "loaddata.php",    success: function(data) {        var a1=data.a1;        var a2=data.a2;        var a3=data.a3;        var a4=data.a4;        // do something with a1, a2, a3 and a4    }});

如果你想

a1

a2

a3

a4

echo json_enpre(array(    "a1" => json_depre($a1),    "a2" => json_depre($a2),    "a3" => json_depre($a3),    "a4" => json_depre($a4)));