In Java, we can use substring(0, 1).toUpperCase() + str.substring(1) to make the first letter of a String as a capital letter (uppercase letter)

String str = "thecognize";

String str1 = str.substring(0, 1).toUpperCase();  // first letter = T

String str2 = str.substring(1);     // after 1 letter = hecognize

String result = str.substring(0, 1).toUpperCase() + str.substring(1); // T + hecognize

 

Output

Terminal

Thecognize

 

2. Apache Commons Lang 3, StringUtils

Alternatively, we can use the Apache commons-lang3 library, StringUtils.capitalize(str) API to capitalize the first letter of a String in Java.

pom.xml

<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
    <version>3.12.0</version>
</dependency>

UppercaseFirstLetter.java

package com.thecognize.string;

import org.apache.commons.lang3.StringUtils;

public class UppercaseFirstLetter {

    public static void main(String[] args) {

        System.out.println(StringUtils.capitalize("thecognize"));   // Thecognize

    }

}

Output

Terminal

Thecognize