[英]String formatting with variable number of arguments in java
Consider a string. 考虑一个字符串。
String Str = "Entered number = %d and string = %s"
Let us say I have a list of objects 让我们说我有一个对象列表
List<Objects> args = new ArrayList<Objects>();
args.add(1);
args.add("abcd");
Is there any way in which I can substitute these args into Str , so that i get a string like "Entered number = 1 and string = abcd "
? 有没有什么方法可以将这些args替换成Str,这样我就得到一个像
"Entered number = 1 and string = abcd "
?
By generalizing this I was planning to dump all the questions and arguments in a file (like json) and execute them at run time. 通过概括,我计划将所有问题和参数转储到文件(如json)中,并在运行时执行它们。 Please do let me know if there are better ways to do this.
如果有更好的方法,请告诉我。
Try: 尝试:
String formatted = String.format(str, args.toArray());
This gives: 这给出了:
Entered number = 1 and string = abcd
You can use the following: 您可以使用以下内容:
String str = "Entered number = %d and string = %s";
List<Object> args = new ArrayList<Object>();
args.add(1);
args.add("abcd");
System.out.println(String.format(str, args.toArray()));
will give the output: 会给出输出:
Entered number = 1 and string = abcd
From JLS 8.4.1 Format parameters : 来自JLS 8.4.1格式参数 :
The last formal parameter in a list is special;
it may be a variable arity parameter, indicated by an
elipsis following the type.
If the last formal parameter is a variable arity parameter of type T,
it is considered to define a formal parameter of type T[].
The method is then a variable arity method. Otherwise, it is a fixed arity
method. Invocations of a variable arity method may contain more actual
argument expressions than formal parameters. All the actual argument
expressions that do not correspond to the formal parameters preceding
the variable arity parameter will be evaluated and the results stored
into an array that will be passed to the method invocation.
See this question on StackOverflow ! 在StackOverflow上看到这个问题!
final String myString = String.format(Str, 1, "abcd");
适当使用变量
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.