我正在编写一个Javascript函数来为表中的每一行着色不同的颜色。 为什么我的代码不起作用？

Question

My understanding of the function I've written is that any table will be subject to this function through the getElementsByTag selector.

Then, the row count is detected to allow for traversal in the for loop.

Then the current row is defined by "row" and if the current i value is odd, the row will be colored red.

But that is not what is happening so I was hoping for some insights, please?

function tableHighlight(){  
    var table = document.getElementsByTagName("table");
    var rowCount = table.rows.length;

        for(var i=1; i<rowCount; i++) {
             var row = table.rows[i];
         if(i%2 != 0){
            row.style.background="#000000";
        }
         }
}

Answer 1

when you use getElementsByTagName, it returns you a list

function tableHighlight(){  
    var table = document.getElementsByTagName("table")[0];
    var rowCount = table.rows.length;

        for(var i=1; i<rowCount; i++) {
             var row = table.rows[i];
         if(i%2 != 0){
            row.style.background="#000000";
        }
         }
}