ArrayList<ArrayList<Object>> a =newArrayList<>(); // 打造这样一个数据的集合 [[1,2],[2,3]] 要求 生成字符串 [1,2]#[2,3]for(inti =0; i <2; i++) { ArrayList<Object> c =newArrayList<>(); c.add(i+1); c.add(i+2); a.add(c);//打印单个子集合的字符串形式数据Log.i("my...
i));}// 使用toString方法longstart1=System.currentTimeMillis();StringBuildersb=newStringBuilder();for(Personp:personList){sb.append(p.toString());}Stringresult1=sb.toString();longend1=System.currentTimeMillis();System.out.println("toString method: "+(end1-start1)+"ms"...
在自定义ArrayList Java中创建toString方法 如果索引i不等于for循环接受的最后一个索引,只需添加if条件即可添加逗号 @Override public String toString() { StringBuilder sb = new StringBuilder(); if(store == null) { return "[]"; } else { for (int i = 0; i < size; i++) { sb.append(store[...
If the array contains other arrays as elements, they are converted to strings by the Object#toString method inherited from Object, which describes their identities rather than their contents. The value returned by this method is equal to the value that would be returned by Arrays.asList(a)....
It is possible becauseObjectclass is the root of class hierarchy in Java. And, all the subclasses and arrays can use the method of theObject. Note: We can also use thetoString()method for theArrayListclass. To learn more, visitJava ArrayList toString()....
2 List<String> list = new ArrayList<>(); 3 int repeated = 0; 4 for (int i = 0; i < size; i++) { 5 Object obj = new Object(); 6 if (list.contains(obj.toString())) { 7 System.out.println("Object " + obj.toString() + " has repeated!"); ...
importjava.lang.reflect.Field;importjava.lang.reflect.Modifier;importjava.util.ArrayList;publicclassObjectAnalyzer{privateArrayList<Object> visited =newArrayList<Object>();publicstaticvoidmain(String[] args){// TODO Auto-generated method stubArrayList<Integer> squaresArrayList =newArrayList<Integer>();for(...
String concatenated = list.stream()... //concatenate here with toString() method from java.lang.Integer class Suppose that list contains integers 1 , 2 and 3 , I expect that concatenated is "123" 或"1,2,3"。 原文由 mat_boy 发布,翻译遵循 CC BY-SA 4.0 许可协议 java...
前几天,我通过手动将类的每个元素写成一个字符串,为Java语言中的一个类编写了一个toString()方法,我突然想到,使用反射可以创建一个可以在所有类上工作的通用toString()方法。ArrayList(field.length); String cf = field[i].toString); classFields.add(cf.substring( ...
Enum.ToString具有以下重载: string ToString();string ToString (string? format);// and two obsolete overloads 寻找正确的参数类型,就可以了: var toStringMethod = typeof(Enum).GetMethod("ToString", new Type[0]); or: var toStringMethod = typeof(Enum).GetMethod("ToString", new[] { typeof(...