Android capitalize first letter

Capitalize the first letter of a string in Java

September 14, 2019 • Atta

In this quick tutorial, you will learn how to capitalize the first letter of a string in Java. Unfortunately, the String class in Java does not provide any method to capitalize string. However, there are methods available to change the case of the string (uppercase, lowercase, etc.).

Using String.substring() Method

The simplest way to capitalize the first letter of a string in Java is by using the String.substring() method:

The above example transforms the first letter of string str to uppercase and leaves the rest of the string the same. If the string is null or empty, the above code throws an exception.

However, we can write a functional capitalize() that makes sure the string has at least one character before using the substring() method:

Now just call the capitalize() method whenever you want to make the first letter of a string uppercase:

Notice the 2nd line of the above code snippet, only the first letter is capitalized. If you want to ensure only the first letter is in uppercase and the remaining string is lowered case, you can do the following:

Using Apache Commons Lang

The Apache Commons Lang library is another way to capitalize the first letter of a string in Java. If you are using Gradle, add the following dependency to your build.gradle file:

For Maven, add the dependency below to your pom.xml file:

The StringUtils class from Commons Lang provides the capitalize() method to change the first letter to uppercase:

Apache Commons Lang offers many extra methods that are not included in standard Java libraries ( java.lang package). It includes String manipulation methods, basic numerical methods, object reflection, concurrency, creation and serialization, and System properties.

Conclusion

In this quick article, we looked at different ways to capitalize the first letter of a string in Java. The simple approach is to use the String class’s substring() method. However, if you are already using Apache Commons Lang in your project, just use the StringUtils class to capitalize the first letter of a string.

Since string capitalization is a very common task in all programming languages, I have also written a tutorial to do the same in JavaScript. Take a look at this guide.

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Java Capitalize First Letter Example

Posted by: Firouzeh hejazi in Core Java October 22nd, 2019 1 Comment Views

In this post, we feature a comprehensive Java Capitalize First Letter Example. We want to write a Java program to convert uppercase first letter java in a sentence and if any character apart from the first one is in Uppercase then convert in into Lowercase.

1. Introduction

Firstly, lets see how to capitalize the first letter of a single word, Example01:

Now we want to capitalize eache word in a sentence:

2. Java Capitalize First Letter – Different Methods

2.1 Method 1

We conver the given string to a char array and conver the first character of each word into upper-case and the rest of its charachters convert into lower-case. See Example02:

2.2 Alternative implementations

2.2.1 Example03

Another way of implementing the previous example is shown in Example03:

2.2.2 Example04

We can also use split() method to separate the given sentence into separate words, see Example04: StringCapital.java Output:

2.2.3 Example05

Lets see another way of implementation in Example05: CaptAnySent.java Output:

2.3 Method 2: Using Java Inbuilt methods toUpperCase()

We can use the toLowerCase() method to convert the string into lowercase format. Iterate the string, if any space found in previous iteration and the current element is not space then it shows that current letter is the starting of the word so call the toUpperCase() method to put the first letter of word in uppercase format and append the string in buffer. Below is the implementation of Example06: InbuiltCapt.java Output:

2.4 Method 3: Using Java Inbuilt methods WordUtils.capitalizeFully(String str)

Inorder to use WordUtils.capitalizeFully(String) we create a Maven project and add this dependency to its pom.xml . See Example07:

Now we can use the method as below: CaptFull.java Output:

This was an article about how to create an uppercase first letter in Java.

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Capitalize the first letter of each word in a string using Java

сентября 14, 2019 • Atta

In this short guide, you will learn how to capitalize the first letter of each word in a string using Java. We have already learned to capitalize the first letter of a string in Java but doing so for each word is a bit tricky.

Using Java 8 Streams

The easiest way to capitalize the first character of each word of a string is by using Java 8 Stream API:

In the above example, we first split the string into an array using the split() method. The array is passed to Arrays.stream() as a parameter that turns it into a Stream object. Afterward, we use the map() method from streams to capitalize each word before converting it back to a string using the collect() method.

If the string is empty or null , the above code will throw an exception. Let us write a function capitalizeAll() that makes sure there is no exception while transforming string:

Here are few examples that use the above function to capitalize the first character of each word:

The above solution only changes the first letter of each word while all other characters remain the same.

Sometimes, you want to make sure that only and only the first character of a word is capitalized. Let us write another function capitalizeFully() for this:

The only difference between capitalizeAll() and capitalizeFully() is that the latter function explicitly changes the remaining part of the word to lowercase:

Using String.replaceAll() Method

If you are using Java 9 or higher, it is possible to use a regular expression with String.replaceAll() method to capitalize the first letter of each word in a string. The String.replaceAll() method replaces each substring of this string that matches the given regular expression with the given replacement. Here is an example:

Let us have some examples:

Using Apache Commons Text

The Apache Commons Text library is yet another option available to convert the first character of each word in a string to uppercase. Add the following dependency to your build.gradle file:

For Maven project, you need to add the following to your pom.xml file:

Now you can use the capitalize() method from WordUtils class to capitalize each word in a string:

The good thing about WordUtils methods is that they handle the exceptions gracefully. There won’t be any exception even if the input is null .

The WordUtils class also provides capitalizeFully() method that capitalizes the first character and turns the remaining characters of each word to lowercase:

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How to Capitalize the First Letter of Each Word in JavaScript – a JS Uppercase Tutorial

In this article, you are going to learn how to capitalize the first letter of any word in JavaScript. After that, you are going to capitalize the first letter of all words from a sentence.

The beautiful thing about programming is that there is no one universal solution to solve a problem. Therefore, in this article you are going to see multiple ways of solving the same problem.

Capitalize the first letter of a word

First of all, let’s start with capitalizing the first letter of a single word. After you learn how to do this, we’ll proceed to the next level – doing it on every word from a sentence. Here is an example:

In JavaScript, we start counting from 0. For instance, if we have an array, the first position is 0, not 1.

Also, we can access each letter from a String in the same way that we access an element from an array. For instance, the first letter from the word «freeCodeCamp» is at position 0.

This means that we can get the letter f from freeCodeCamp by doing publication[0] .

In the same way, you can access other letters from the word. You can replace «0» with any number, as long as you do not exceed the word length. By exceeding the word length, I mean trying to do something like publication[25 , which throws an error because there are only twelve letters in the word «freeCodeCamp».

How to capitalize the first letter

Now that we know how to access a letter from a word, let’s capitalize it.

In JavaScript, we have a method called toUpperCase() , which we can call on strings, or words. As we can imply from the name, you call it on a string/word, and it is going to return the same thing but as an uppercase.

Running the above code, you are going to get a capital F instead of f. To get the whole word back, we can do this:

Now it concatenates «F» with «reeCodeCamp», which means we get back the word «FreeCodeCamp». That is all!

Let’s recap

To be sure things are clear, let’s recap what we’ve learnt so far:

• In JavaScript, counting starts from 0.
• We can access a letter from a string in the same way we access an element from an array — e.g. string[index] .
• Do not use an index that exceeds the string length (use the length method — string.length — to find the range you can use).
• Use the built-in method toUpperCase() on the letter you want to transform to uppercase.

Capitalize the first letter of each word from a string

The next step is to take a sentence and capitalize every word from that sentence. Let’s take the following sentence:

Split it into words

We have to capitalize the first letter from each word from the sentence freeCodeCamp is an awesome resource .

The first step we take is to split the sentence into an array of words. Why? So we can manipulate each word individually. We can do that as follows:

Iterate over each word

After we run the above code, the variable words is assigned an array with each word from the sentence. The array is as follows [«freeCodeCamp», «is», «an», «awesome», «resource»] .

Now the next step is to loop over the array of words and capitalize the first letter of each word.

In the above code, every word is taken separately. Then it capitalizes the first letter, and in the end, it concatenates the capitalized first letter with the rest of the string.

Join the words

What is the above code doing? It iterates over each word, and it replaces it with the uppercase of the first letter + the rest of the string.

If we take «freeCodeCamp» as an example, it looks like this freeCodeCamp = F + reeCodeCamp .

After it iterates over all the words, the words array is [«FreeCodeCamp», «Is», «An», «Awesome», «Resource»] . However, we have an array, not a string, which is not what we want.

The last step is to join all the words to form a sentence. So, how do we do that?

In JavaScript, we have a method called join , which we can use to return an array as a string. The method takes a separator as an argument. That is, we specify what to add between words, for example a space.

In the above code snippet, we can see the join method in action. We call it on the words array, and we specify the separator, which in our case is a space.

Therefore, [«FreeCodeCamp», «Is», «An», «Awesome», «Resource»] becomes FreeCodeCamp Is An Awesome Resource .

Other methods

In programming, usually, there are multiple ways of solving the same problem. So let’s see another approach.

What is the difference between the above solution and the initial solution? The two solutions are very similar, the difference being that in the second solution we are using the map function, whereas in the first solution we used a for loop .

Let’s go even further, and try to do a one-liner. Be aware! One line solutions might look cool, but in the real world they are rarely used because it is challenging to understand them. Code readability always comes first.

The above code uses RegEx to transform the letters. The RegEx might look confusing, so let me explain what happens:

• ^ matches the beginning of the string.
• \w matches any word character.
• <1>takes only the first character.
• Thus, ^\w <1>matches the first letter of the word.
• | works like the boolean OR . It matches the expression after and before the | .
• \s+ matches any amount of whitespace between the words (for example spaces, tabs, or line breaks).

Thus, with one line, we accomplished the same thing we accomplished in the above solutions. If you want to play around with the RegEx and to learn more, you can use this website.

Conclusion

Congratulations, you learnt a new thing today! To recap, in this article, you learnt how to:

• access the characters from a string
• capitalize the first letter of a word
• split a string in an array of words
• join back the words from an array to form a string
• use RegEx to accomplish the same task

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