使用usort对二维数组进行排序

<?php


$lang =[
            ["html"=>"前台语言","难易度"=>60],
            ["css"=>"前台样式","难易度"=>50],
            ["javascript"=>"前端脚本","难易度"=>80],
            ["php"=>"后端脚本","难易度"=>75]
    ];


echo "<pre>".var_export($lang,true),"<hr>";

usort($lang,function($a,$b){
    return strcmp($a["难易度"],$b["难易度"]);
});

echo "<pre>".var_export($lang,true),"<hr>";


?>