public?class?HelloWorld?{
????public?static?void?main(String[]?args)?{
????????
		double?m?=?78.5;
		//將基本類型轉換為字符串
		String?str1?=?Double.toString(m);
????????
		System.out.println("m?轉換為String型后與整數20的求和結果為：?"+(str1+20));
		
		String?str?=?"180.20";
	????//?將字符串轉換為基本類型
		Double?a?=?Double.valueOf(str);
	
		System.out.println("str?轉換為double型后與整數20的求和結果為：?"+(a+20));
	}
}

點擊提交顯示是對的，但是為右側的顯示是報錯？？我寫錯了么？？還是瀏覽器問題？？

error: no suitable method found for toString(double)
String str1 = Integer.toString(m); ;
^
method Integer.toString() is not applicable
(actual and formal argument lists differ in length)
method Integer.toString(int) is not applicable
(actual argument double cannot be converted to int by method invocation conversion)
method Integer.toString(int,int) is not applicable
(actual and formal argument lists differ in length)
method Object.toString() is not applicable
(actual and formal argument lists differ in length)
error: cannot find symbol
Double a = Integer.valueof(str); ;
^
symbol: method valueof(String)
location: class Integer
2 errors