java remove all letters from string code example

Example 1: java remove non numbers from string

String str = "a12.334tyz.78x";
str = str.replaceAll("[^\\d.]", "");

Example 2: how to remove letters from string java

public extractLetters(String str){
	String result="";
	for(int i= 0; i< str.length; i++){
	    if(Character.isLetter(str.charAt(i))){
	    result+=str.charAt(i);
	  	}
	}

Example 3: how to remove all characters before a certain character from a string in java

String s = "the text=text";
String s1 = s.substring(s.indexOf("=")+1);
s1.trim();