In Java, How Can A String Be Determined If It Is Numeric?

There are multiple ways to check if a String is numeric in Java. Here are three common approaches:

  1. Using try-catch block with NumberFormatException:
public boolean isNumeric(String str) {
    try {
        Double.parseDouble(str);
        return true;
    } catch (NumberFormatException e) {
        return false;
    }
}
  1. Using regular expression:
public boolean isNumeric(String str) {
    return str.matches("-?\\d+(\\.\\d+)?");
}
  1. Using Apache Commons Lang library:
import org.apache.commons.lang3.StringUtils;

public boolean isNumeric(String str) {
    return StringUtils.isNumeric(str);
}

All three approaches will return true if the String is numeric and false otherwise.

About the Author Rex

I'm a passionate tech blogger with an insatiable love for programming! From my early days tinkering with code, I've delved into web dev, mobile apps, and AI. Sharing insights and tutorials with the world is my joy, connecting me to a global community of like-minded tech enthusiasts. Python holds a special place in my heart, but I embrace all challenges. Constantly learning, I attend tech conferences, contribute to open-source projects, and engage in code review sessions. My ultimate goal is to inspire the next generation of developers and contribute positively to the ever-evolving tech landscape. Let's code together!