javascript - 小计算问题

Question

我对javascript计算有一个小问题。我有这样的功能：

$( "#main-nav li[class]" ).each(function( index ) {
     var position = $(this).offset();
     var width = $(this).width();
     var center = parseInt(position) - (parseInt(width) / 2);
     console.log("Position: " + position.left + ", width: " + width +  ", center: " + center);
});   

但它导致了这一点。任何人都知道如何不进行计算？

Position: 722, width: 83, center: NaN 

Answer 1

给position.left

$( "#main-nav li[class]" ).each(function( index ) {
     var position = $(this).offset();
     var width = $(this).width();
     var center = parseInt(position.left) - (parseInt(width) / 2);
     console.log("Position: " + position.left + ", width: " + width +  ", center: " + center);
}); 

Answer 2

只需在这条线上进行简单的更正。然后你会得到想要的输出..

var center = parseInt(position.left) - (parseInt(width) / 2);