Reverse Strings in JAVA | (simple & easy) 

Glad it helped!

just keep coding :) if u dont know what to code go learn something new and maybe some cool ideas will pop into ur head!

You're welcome!

Glad it was helpful!

Your way works and is more simple than my way, however this video is supposed to teach those who don’t know how to reverse a sting WITHOUT StringBuilder. (For example in a AP CSA class they would ask you to do this without StringBuilder)

interviews tend to not allow things like StringBuilder, while yes it is more efficient, they want to see if you know the fundamental logic

Glad it was helpful!

Using str.length gives you the length of a string but since getting a char from a string starts at 0 not 1, we need to go back one to get the last letter. For example if we had the string “Hello”, and we got the length it would be 5 but if we got the 5th letter AND start counting from 0 not 1 then we we would have an issue because we would go 0, 1, 2, 3, 4, 5 and if you look closely I just listed 6 numbers. So really using the length you are getting the 6th letter here of a 5 letter word. That’s why we subtract one.

@@mintype thx understood

Thanks a lot 😊

oh yea thanks

yw

Thanks

-1 means the index of last character, because index starts from zero, so when you want to get last characters' index you should add this -1

array {1, 2, 3, 4, 5} There's 5 elements inside, it has a length of 5. However, if we want to know the index of each element inside the array the value '1' is at position '0' which means element '5' is at position '4', so to get the value '5' we need to write array[4]. given N is the length of the array, n-1 determins the position of those elements. If simple wrote i = str.length; you would get an out of bounds exception element because the element '5' is at position '4', not position '5'. Following the formular n-1, we say str.-length-1 to ensure we always end up at the last element contained within the array.

Thank you for your valuable information

@@DecartesGreatStar You're amazing!

send ur code here

the plus makes it so the thing after gets ADDED to the string. so the string starts off with nothing in it and each time it goes through the for loop, one letter from the str string is added to result. (it goes backwards so its reversed.)

you can set the original string variable's value to the result string variable's value like so: str = result;

@@mintype what if you wanted to change the string itself inside the loop rather than creating a empty string to store the reversed version on. (thxs for the reply btw, i'm new so that helped)

@@pradipacharya3168 I've done some research and if you wanted to change the string itself inside the loop rather than create an empty string to store the reversed version to, that wouldn't really work. However, this video is to show people how to reverse strings using a for loop, like how they may expect a student to in a computer science class. If you really wanted to reverse a string in less lines of code etc., you could do the following: String originalString = "Hello, world!"; StringBuilder reversedString = new StringBuilder(originalString).reverse(); System.out.println(reversedString); // prints "!dlrow ,olleH"

@@mintype thank you man, that helped a lot!

glad it helped!

yw

Thanks

StringBuilder is another way you could do this. However, I am teaching how to do this manually, because in schools, teachers don't want you to take shortcuts.

Can you provide some info? Like give me your code so I can see whats wrong. Also maybe tell me your version of Java? New Java versions come out all the time and can break old code. discord help server: discord.gg/hhGu6mV5wm

??? What went wrong?

@@mintype o ol oll olle olleh this is the actual output what i got

Isn’t that hello backwards though? “olleh”

You have a ; (semicolon) at the end of your for loop!!!! updated code: String input ="Hello world!"; String output=" "; for(int i=input.length()-1;i>=0;i--) output+=input.charAt(i); System.out.println(output);

@@mintype Thank you so much!

Thank you

Thank you

Thank you

danke

@@mintype dahnke