常用的javascript函数

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//计算位置
function setOffsets() {
            var end = offsetEl.offsetWidth;
            var top = calculateOffsetTop(offsetEl);
            dataDiv.style.border = "black 1px solid";
            dataDiv.style.left = end + 15 + "px";
            dataDiv.style.top = top + "px";
        }
        
        function calculateOffsetTop(field) {
          return calculateOffset(field, "offsetTop");
        }

        function calculateOffset(field, attr) {
          var offset = 0;
          while(field) {
            offset += field[attr]; 
            field = field.offsetParent;
          }
          return offset;
        }
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