I am using Java to get a String
input from the user. I am trying to make the first letter of this input capitalized.
I tried this:
String name;
BufferedReader br = new InputStreamReader(System.in);
String s1 = name.charAt(0).toUppercase());
System.out.println(s1 + name.substring(1));
which led to these compiler errors:
Type mismatch: cannot convert from InputStreamReader to BufferedReader
Cannot invoke toUppercase() on the primitive type char
String str = "java";
String cap = str.substring(0, 1).toUpperCase() + str.substring(1);
// cap = "Java"
With your example:
public static void main(String[] args) throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
// Actually use the Reader
String name = br.readLine();
// Don't mistake String object with a Character object
String s1 = name.substring(0, 1).toUpperCase();
String nameCapitalized = s1 + name.substring(1);
System.out.println(nameCapitalized);
}
StringUtils.capitalize(..)
from commons-lang
StringUtils.capitalize( "fred from jupiter" );
produces "Fred from jupiter"
. Easy ... :D
The shorter/faster version code to capitalize the first letter of a String is:
String name = "stackoverflow";
name = name.substring(0,1).toUpperCase() + name.substring(1).toLowerCase();
the value of name
is "Stackoverflow"
Use Apache's common library. Free your brain from these stuffs and avoid Null Pointer & Index Out Of Bound Exceptions
Step 1:
Import apache's common lang library by putting this in build.gradle
dependencies
compile 'org.apache.commons:commons-lang3:3.6'
Step 2:
If you are sure that your string is all lower case, or all you need is to initialize the first letter, directly call
StringUtils.capitalize(yourString);
If you want to make sure that only the first letter is capitalized, like doing this for an enum
, call toLowerCase()
first and keep in mind that it will throw NullPointerException
if the input string is null.
StringUtils.capitalize(YourEnum.STUFF.name().toLowerCase());
StringUtils.capitalize(yourString.toLowerCase());
Here are more samples provided by apache. it's exception free
StringUtils.capitalize(null) = null
StringUtils.capitalize("") = ""
StringUtils.capitalize("cat") = "Cat"
StringUtils.capitalize("cAt") = "CAt"
StringUtils.capitalize("'cat'") = "'cat'"
Note:
WordUtils
is also included in this library, but is deprecated. Please do not use that.
Java:
simply a helper method for capitalizing every string.
public static String capitalize(String str)
{
if(str == null || str.length()<=1) return str;
return str.substring(0, 1).toUpperCase() + str.substring(1);
}
After that simply call str = capitalize(str)
Kotlin:
str.capitalize()
if you use SPRING:
import static org.springframework.util.StringUtils.capitalize;
...
return capitalize(name);
IMPLEMENTATION: org/springframework/util/StringUtils.java#L535-L555
REF: javadoc-api/org/springframework/util/StringUtils.html#capitalize
NOTE: If you already have Apache Common Lang dependency, then consider using their StringUtils.capitalize as other answers suggest.
What you want to do is probably this:
s1 = name.substring(0, 1).toUpperCase() + name.substring(1);
(converts first char to uppercase and adds the remainder of the original string)
Also, you create an input stream reader, but never read any line. Thus name
will always be null
.
This should work:
BufferedReader br = new InputstreamReader(System.in);
String name = br.readLine();
String s1 = name.substring(0, 1).toUpperCase() + name.substring(1);
WordUtils.capitalize(java.lang.String)
from Apache Commons.
Below solution will work.
String A = "stackOverflow";
String ACaps = A.toUpperCase().charAt(0)+A.substring(1,A.length());
//Will print StackOverflow
You can't use toUpperCase() on primitive char , but you can make entire String to Uppercase first then take the first char, then to append to the substring as shown above.
Use this utility method to get all first letter in capital.
String captializeAllFirstLetter(String name)
{
char[] array = name.toCharArray();
array[0] = Character.toUpperCase(array[0]);
for (int i = 1; i < array.length; i++) {
if (Character.isWhitespace(array[i - 1])) {
array[i] = Character.toUpperCase(array[i]);
}
}
return new String(array);
}
Set the string to lower case, then set the first Letter to upper like this:
userName = userName.toLowerCase();
then to capitalise the first letter:
userName = userName.substring(0, 1).toUpperCase() + userName.substring(1).toLowerCase();
substring is just getting a piece of a larger string, then we are combining them back together.
String str1 = "hello";
str1.substring(0, 1).toUpperCase()+str1.substring(1);
IT WILL WORK 101%
public class UpperCase {
public static void main(String [] args) {
String name;
System.out.print("INPUT: ");
Scanner scan = new Scanner(System.in);
name = scan.next();
String upperCase = name.substring(0, 1).toUpperCase() + name.substring(1);
System.out.println("OUTPUT: " + upperCase);
}
}
Here is my detailed article on the topic for all possible options Capitalize First Letter of String in Android
Method to Capitalize First Letter of String in Java
public static String capitalizeString(String str) {
String retStr = str;
try { // We can face index out of bound exception if the string is null
retStr = str.substring(0, 1).toUpperCase() + str.substring(1);
}catch (Exception e){}
return retStr;
}
Method to Capitalize First Letter of String in KOTLIN
fun capitalizeString(str: String): String {
var retStr = str
try { // We can face index out of bound exception if the string is null
retStr = str.substring(0, 1).toUpperCase() + str.substring(1)
} catch (e: Exception) {
}
return retStr
}
Shortest too:
String message = "my message";
message = Character.toUpperCase(message.charAt(0)) + message.substring(1);
System.out.println(message) // Will output: My message
Worked for me.
In Android Studio
Add this dependency to your build.gradle (Module: app)
dependencies {
...
compile 'org.apache.commons:commons-lang3:3.1'
...
}
Now you can use
String string = "STRING WITH ALL CAPPS AND SPACES";
string = string.toLowerCase(); // Make all lowercase if you have caps
someTextView.setText(WordUtils.capitalize(string));
What about WordUtils.capitalizeFully()?
import org.apache.commons.lang3.text.WordUtils;
public class Main {
public static void main(String[] args) {
final String str1 = "HELLO WORLD";
System.out.println(capitalizeFirstLetter(str1)); // output: Hello World
final String str2 = "Hello WORLD";
System.out.println(capitalizeFirstLetter(str2)); // output: Hello World
final String str3 = "hello world";
System.out.println(capitalizeFirstLetter(str3)); // output: Hello World
final String str4 = "heLLo wORld";
System.out.println(capitalizeFirstLetter(str4)); // output: Hello World
}
private static String capitalizeFirstLetter(String str) {
return WordUtils.capitalizeFully(str);
}
}
You can also try this:
String s1 = br.readLine();
char[] chars = s1.toCharArray();
chars[0] = Character.toUpperCase(chars[0]);
s1= new String(chars);
System.out.println(s1);
This is better(optimized) than with using substring. (but not to worry on small string)
You can use substring()
to do this.
But there are two different cases:
Case 1
If the String
you are capitalizing is meant to be human-readable, you should also specify the default locale:
String firstLetterCapitalized =
myString.substring(0, 1).toUpperCase(Locale.getDefault()) + myString.substring(1);
Case 2
If the String
you are capitalizing is meant to be machine-readable, avoid using Locale.getDefault()
because the string that is returned will be inconsistent across different regions, and in this case always specify the same locale (for example, toUpperCase(Locale.ENGLISH)
). This will ensure that the strings you are using for internal processing are consistent, which will help you avoid difficult-to-find bugs.
Note: You do not have to specify Locale.getDefault()
for toLowerCase()
, as this is done automatically.
TO get First letter capital and other wants to small you can use below code. I have done through substring function.
String currentGender="mAlE";
currentGender=currentGender.substring(0,1).toUpperCase()+currentGender.substring(1).toLowerCase();
Here substring(0,1).toUpperCase() convert first letter capital and substring(1).toLowercase() convert all remaining letter into a small case.
OUTPUT:
Male
try this one
What this method does is that, Consider the word "hello world" this method turn it into "Hello World" capitalize the beginning of each word .
private String capitalizer(String word){
String[] words = word.split(" ");
StringBuilder sb = new StringBuilder();
if (words[0].length() > 0) {
sb.append(Character.toUpperCase(words[0].charAt(0)) + words[0].subSequence(1, words[0].length()).toString().toLowerCase());
for (int i = 1; i < words.length; i++) {
sb.append(" ");
sb.append(Character.toUpperCase(words[i].charAt(0)) + words[i].subSequence(1, words[i].length()).toString().toLowerCase());
}
}
return sb.toString();
}
Existing answers are either
incorrect: they think that char is a separate character (code point), while it is a UTF-16 word which can be a half of a surrogate pair, or
use libraries which is not bad itself but requires adding dependencies to your project, or
use Java 8 Streams which is perfectly valid but not always possible.
Let's look at surrogate characters (every such character consist of two UTF-16 words — Java char
s) and can have upper and lowercase variants:
IntStream.rangeClosed(0x01_0000, 0x10_FFFF)
.filter(ch -> Character.toUpperCase(ch) != Character.toLowerCase(ch))
.forEach(ch -> System.out.print(new String(new int[] { ch }, 0, 1)));
Many of them may look like 'tofu' (□) for you but they are mostly valid characters of rare scripts and some typefaces support them.
For example, let's look at Deseret Small Letter Long I (𐐨), U+10428, "\uD801\uDC28"
:
System.out.println("U+" + Integer.toHexString(
"\uD801\uDC28".codePointAt(0)
)); // U+10428
System.out.println("U+" + Integer.toHexString(
Character.toTitleCase("\uD801\uDC28".codePointAt(0))
)); // U+10400 — ok! capitalized character is another code point
System.out.println("U+" + Integer.toHexString(new String(new char[] {
Character.toTitleCase("\uD801\uDC28".charAt(0)), "\uD801\uDC28".charAt(1)
}).codePointAt(0))); // U+10428 — oops! — cannot capitalize an unpaired surrogate
So, a code point can be capitalized even in cases when char
cannot be. Considering this, let's write a correct (and Java 1.5 compatible!) capitalizer:
@Contract("null -> null")
public static CharSequence capitalize(CharSequence input) {
int length;
if (input == null || (length = input.length()) == 0) return input;
return new StringBuilder(length)
.appendCodePoint(Character.toTitleCase(Character.codePointAt(input, 0)))
.append(input, Character.offsetByCodePoints(input, 0, 1), length);
}
And check whether it works:
public static void main(String[] args) {
// ASCII
System.out.println(capitalize("whatever")); // w -> W
// UTF-16, no surrogate
System.out.println(capitalize("что-то")); // ч -> Ч
// UTF-16 with surrogate pairs
System.out.println(capitalize("\uD801\uDC28")); // 𐐨 -> 𐐀
}
See also:
surrogate pairs What is a "surrogate pair" in Java?
upper case vs. title case https://stackoverflow.com/a/47887432/3050249
Current answers are either incorrect or over-complicate this simple task. After doing some research, here are two approaches I come up with:
1. String's substring()
Method
public static String capitalize(String str) {
if(str== null || str.isEmpty()) {
return str;
}
return str.substring(0, 1).toUpperCase() + str.substring(1);
}
Examples:
System.out.println(capitalize("java")); // Java
System.out.println(capitalize("beTa")); // BeTa
System.out.println(capitalize(null)); // null
2. Apache Commons Lang
The Apache Commons Lang library provides StringUtils
the class for this purpose:
System.out.println(StringUtils.capitalize("apache commons")); // Apache commons
System.out.println(StringUtils.capitalize("heLLO")); // HeLLO
System.out.println(StringUtils.uncapitalize(null)); // null
Don't forget to add the following dependency to your pom.xml
file:
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>3.9</version>
</dependency>
StringUtils.capitalize("a")
.
Simple solution! doesn't require any external library, it can handle empty or one letter string.
private String capitalizeFirstLetter(@NonNull String str){
return str.length() == 0 ? str
: str.length() == 1 ? str.toUpperCase()
: str.substring(0, 1).toUpperCase() + str.substring(1).toLowerCase();
}
This is just to show you, that you were not that wrong.
BufferedReader br = new InputstreamReader(System.in);
// Assuming name is not blank
String name = br.readLine();
//No more error telling that you cant convert char to string
String s1 = (""+name.charAt(0)).toUppercase());
// Or, as Carlos prefers. See the comments to this post.
String s1 = Character.toString(name.charAt(0)).toUppercase());
System.out.println(s1+name.substring(1));
Note: This is not at all the best way to do it. This is just to show the OP that it can be done using charAt()
as well. ;)
Character.toString(name.charAt(0))
instead of ""+name.charAt(0)
for showing what I really want to do.
This will work
char[] array = value.toCharArray();
array[0] = Character.toUpperCase(array[0]);
String result = new String(array);
You can use the following code:
public static void main(String[] args) {
capitalizeFirstLetter("java");
capitalizeFirstLetter("java developer");
}
public static void capitalizeFirstLetter(String text) {
StringBuilder str = new StringBuilder();
String[] tokens = text.split("\\s");// Can be space,comma or hyphen
for (String token : tokens) {
str.append(Character.toUpperCase(token.charAt(0))).append(token.substring(1)).append(" ");
}
str.toString().trim(); // Trim trailing space
System.out.println(str);
}
If Input is UpperCase ,then Use following :
str.substring(0, 1).toUpperCase() + str.substring(1).toLowerCase();
If Input is LowerCase ,then Use following :
str.substring(0, 1).toUpperCase() + str.substring(1);
Using commons.lang.StringUtils
the best answer is:
public static String capitalize(String str) {
int strLen;
return str != null && (strLen = str.length()) != 0 ? (new StringBuffer(strLen)).append(Character.toTitleCase(str.charAt(0))).append(str.substring(1)).toString() : str;
}
I find it brilliant since it wraps the string with a StringBuffer. You can manipulate the StringBuffer as you wish and though using the same instance.
Success story sharing
str.substring(0, 1)
might return invalid unicode string - stackoverflow.com/questions/70178612/…