Reverse the String in Java
Reversing a string means to switch the ordering of the characters in a string. For example, the reverse of the string "Hello!" is "!olleH". There are many ways the reversal of a string can be done in Java.
Steps
Using a Buffer in JDK
- Use the reverse method of the StringBuffer class in the JDK. The code snippet for reverse method is as follows:
public String reverse(String str) {
if ((null == str) || (str.length() <= 1)) {
return str;
}
return new StringBuffer(str).reverse().toString();
}
- Appending to a StringBuffer: StringBuffer is an apt choice to create and manipulate dynamic string information. Reversal using StringBuufer is also an option.
public String reverse(String str) {
if ((null == str) || (str.length() <= 1)) {
return str;
}
StringBuffer reverse = new StringBuffer(str.length());
for (int i = str.length() - 1; i >= 0; i--) {
reverse.append(str.charAt(i));
}
return reverse.toString();
}
}
- A recursive function can also be used to reverse a string.
public String reverse(String str) {
if ((null == str) || (str.length() <= 1)) {
return str;
}
return reverse(str.substring(1)) + str.charAt(0);
}
- CharArray can be used to reverse as follows:
public String reverse(String str) {
if ((null == str) || (str.length() <= 1)) {
return str;
}
char[] chars = str.toCharArray();
int length = chars.length - 1;
for (int i = 0; i < length; i++) {
char tempVar = chars[i];
chars[i] = chars[length];
chars[length--] = tempVar;
}
return new String(chars);
}
Using the Byte Array
- Use the following code to reverse the string via an array. Template:CodeBox
