jquery - 在 jQuery 中计算每个值的总和

Question

如何在 jQuery every 函数中进行计数？

<script>
    ajax();
    function ajax(){
        $.ajax({
            url:"ChinaWeather.json",
            dataType:"json",
            success: function(data){
                $.each(data, function(index, item){ 
                    var sum = 1;
                    $('#countryweatherwrap').append('<div id="countryweather' + sum + '">' + data[index].season + 'Temperatuur: ' +
                        data[index].temperature+' °C <br />' + '<div style="height:'+ data[index].temperature*5.50  +'px;width:100%;border:1px solid #000; background-color:yellow"></div></div>'
                        );  
                    });
            }
        })
    }   
</script>

此时代码返回 <div id="countryweather">在每个循环中。我希望它能够计数，因此它返回 <div id="countryweather2"> , <div id="countryweather3">等等

Answer 1

a.将 var sum 移到每个循环之外(使其全局)
b.通过 ++;

将 sum 的值增加 1

<script>        
    ajax();
    function ajax(){        
        $.ajax({
            url:"ChinaWeather.json",
            dataType:"json",
            success: function(data){
                var sum = 1;
                $.each(data, function(index, item){                    
                    $('#countryweatherwrap').append('<div id="countryweather' + sum + '">' + data[index].season + 'Temperatuur: ' +
                        data[index].temperature+' °C <br />' + '<div style="height:'+ data[index].temperature*5.50  +'px;width:100%;border:1px solid #000; background-color:yellow"></div></div>'                      
                        );  
                      sum++;
                    });
            }
        })
    }   
</script>