MATLAB 的 cell,称单元格数组 or 元胞数组:使用频率特别高,甚至比 struct 结构体还高. MATLAB文档给出的 cell 官方定义: A cell array is a collection of containers called cells in which you can store different types of data. 精华之处就是在可以存储不同类型的数据.可以是Matlab的类型或者自定义的类型. 一个元胞数组的一个单元可能包含:一个实数数组 or 字
mysql text字段判断是否为空 mysql text字段为空select * from `tableName` where `textField` is null or `textField` = ''; mysql text字段不为空select * from `tableName` where `textField` is not null AND `textField` != '';
mybatis判断集合为空或者元素个数为零: <if test="mlhs != null and mlhs.size() != 0"> and t.mlh_name not in <foreach collection="mlhs" item="item1" open="(" close=")" index="i" separator=",">
package com.lanxi.demo2; import java.util.HashSet; import java.util.Iterator; import java.util.Set; public class Test { public static void main(String[] args) { //引用一个Set集合实现类 Set set=new HashSet(); //添加单个元素 set.add("哈"); set.add("士");
1. 'API判断数组为空或没有初始化 Private Declare Function SafeArrayGetDim Lib "oleaut32.dll" (ByRef saArray() As Any) As Long Private Sub Command1_Click()Dim tmp() As StringIf SafeArrayGetDim(tmp) = 0 ThenMsgBox "数组为空或没有初始化"End IfEnd Sub 2. Private