String类和Stringbuffer的转换,强制类型转换

String类和Stringbuffer的转换,强制类型转换

//String--->StringBuffer类转换publicclassDemo8 {publicstaticvoidmain(String[] args) {//定义一个字符串String s ="hello";//报错，错误的转换方式// StringString str="You are nice.";str+="I love you so much.";如果⽤StringBuffer类的话，代码如下：StringBuffer str= new StringBuffer("You are nice.");str.append("I love y

ˇ﹏ˇ * 我们可能要到结果是A类型，所以我们还得转换回来* * String和StringBuffer的互相转换*/publicclassStringBuffer_转换{publicstaticvoidmain(String[]args){//String转换为2.String a = “hello”+“abc”；=> String a = “helloabc”；难：常用方法说明：String类是保存字符串常量的，名称更新都需要重新开辟新的空间，效率较低，因此java设计者还提供了

Stringstr=String.join("拼接符","元素1","元素2",);Stringstr=String.join("-","a","b","c");// str = "a-b-c" 1 2 3 StringBuffer类和StringBuilder类StringBuffer和StringB";StringBufferstringBuffer=newStringBuffer(string1);//String转换为StringBufferStringstring2=stringBuffer.toString();//StringBuffer转换为String 1 2 3

String str=“Hello World.”；StringBuffer buffer = new StringBuffer(); buffer.append(str); 二、String与字符数组的相互转换1、将String转换成字符数组String类成员toStringBuffer replace(start,end,string); // 替换指定位置的字符串void setCharAt(int index, char ch) ; // 修改指定索引的字符串5,反转。StringBuffer re