从字符串中删除动态字符

Question

I have a string containing numbers separated with , . I want to remove the , before the first character.

The input is ,1,2,3,4,5,6,7,8,9,10 , and this code does not work:

results.replaceFirst(",","");

Answer 1

Strings are immutable in Java. Calling a method on a string will not modify the string itself, but will instead return a new string .

In order to capture this new string, you need to assign the result of the operation back to a variable:

results = results.replaceFirst(",", "");

Answer 2

Try this

String str = ",1,2,3,4,5,6,7,8,9,10";
if(Objects.nonNull(str) && str.startsWith(",")){
  str = str.substring(1, str.length());
}

it will remove , at first position

Answer 3

you can also do like this ..

String str = ",1,2,3,4,5,6,7,8,9,10";
String stre = str.replaceFirst("^,", "");
Log.e("abd",stre);

Answer 4

Try this

String str = ",1,2,3,4,5,6,7,8,9,10";
str = str .startsWith(",") ? str .substring(1) : str ;
System.out.println("output"+str);  // 1,2,3,4,5,6,7,8,9,10