Java Code to Remove All Spaces

Case 1 > Using Predefined Method

static void method_1(){
String s1="abc d e f";
System.out.println("OUTPUT M1 = "+s1.replaceAll("\\s", ""));
}

Case 2 > Using charAt() Method

static void method_2(){
String s1="abc d e f";
StringBuffer sb=new StringBuffer();
for(int i=0;i<s1.length();i++){
if(s1.charAt(i)!=' ' ){
sb.append(s1.charAt(i));
}
}
System.out.println("OUTPUT M2 = "+sb);
}