将多个字符串组合成一个JAVA

Question

String dataContainer;

for(String tempString:setInput){
     String finalString = "," + tempString + "," ;   
}

Set<String> setInput = new TreeSet();
setInput.add("Dog");
setInput.add("Cat");
setInput.add("Mouse");

生成字符串：

,Dog,,Cat,,Mouse,

Answer 1

您所做的是每次初始化您的结果字符串。

实际上，你想做

String finalString ="";
for(String tempString:setInput){
      finalString += "," + tempString + "," ;   
}

但是上述方法会导致多个string创建。

 StringBuilder finalStringb =new StringBuilder();
    for(String tempString:setInput){
          finalStringb.append(",").append(tempString).append(",") ;   
    }

String finalS = finalStringb.toString();