前端js代码运行时间console.time和console.timeEnd

计算一段代码的运行时间

[b]
function getSelectedZoneInfo(dialog) {
	// 获取选择的订货城市
console.time('运行时间：');
	var $searchDg = $('#dialog_SearchDataGrid');
	var checkedRows = $searchDg.datagrid('getChecked');
	if ('' == checkedRows || checkedRows.length == 0) {
		showWarn('请选择订货城市，然后确定');
		return;
	}
	var firstFlag = 0;
	$.each(checkedRows, function(index, item) {
		var $dg = $('#storeDetail');
		// 判断城市是否存在
		var allRows = $dg.datagrid("getRows");// 获取所有的行
		var flag = true;
		for ( var index = 0; index < allRows.length; index++) {
			$dg.datagrid("beginEdit", index);
			var storeNoEdit = $dg.datagrid("getEditor", {
				'index' : index,
				'field' : 'storeNo'
			});
			var storeNoT = storeNoEdit.target.val();
			if (storeNoT == item.storeNo) {
				flag = false;
				break;
			}
		}
		if (flag) {
			if (0 == firstFlag) {// 第一次进行赋值
				// 设值
				var nowRow = $dg.datagrid('getSelected');
				var nowIndex = $dg.datagrid('getRowIndex', nowRow);
				$dg.datagrid('selectRow', nowIndex).datagrid('beginEdit',
						nowIndex);
				var storeNoE = $dg.datagrid('getEditor', {
					'index' : nowIndex,
					'field' : 'storeNo'
				});
				var storeNameE = $dg.datagrid('getEditor', {
					'index' : nowIndex,
					'field' : 'storeName'
				});
				storeNoE.target.val(item.storeNo);
				storeNameE.target.val(item.storeName);
			} else {
				$('#storeDetail').datagrid('appendRow', item);
			}
			firstFlag++;
		}
	});
console.timeEnd('运行时间：');
	dialog.close();
}
[/b]