long to String in Java

How to convert a long to a Java String

The easiest way to convert from a long to a String in Java is to add the long to an empty set of double quotes with the plus operator.

// long to String in Java example code
long   longToConvert = 90210L;
String longAsString = "" + longToConvert;
System.out.println( "Converted long to String length " + longAsString.length() );

Convert from long to String in Java

If the empty String addition trick is not to your liking, rest assured there are many ways to convert a long to a String in Java, including:

1. Add it to an empty String, “” + longToConvert
2. The String class’ valueOf method, String.valueOf( longToConvert )
3. The Long class’ toString method,  Long.toString( longToConvert )
4. The String class’ format method,  String.format( “%d”, longToConvert )
5. Use DecmialFormat, new DecimalFormat(“#”).format(longToConvert)

The best solution is the simplest one

The best solution is the simplest solution, and there is no shame in simply using the plus operator and adding a long to an empty String to get the JVM to convert a long to a String for you.

The use of the String class or the Long class to perform a long to String conversion is code bloat your fellow programmers don’t need.

It might look more object oriented, but unless your doing really complex String manipulations that demand the use of the StringBuilder class, a quick concatenation of an empty String with a long primitive type is the way to go.

Example long to String conversion code

Here’s a JShell script you can run that demonstrates the five approaches to the long to String conversion problem listed above:

// Five ways to convert a long to String in Java 
long longToConvert = 90210L;
String longAsString = "";

longAsString = "" = longAsString;
longAsString = String.valueOf( longToConvert );
longAsString = Long.toString( longToConvert );
longAsString = String.format( "%d", longToConvert );
longAsString = new java.text.DecimalFormat("#").format(longToConvert);

// Print out the length of the long converted to a String in Java
System.out.println( "Converted long to Java String length " + longAsString.length() );

Add a long inside a text String

The easiest way to convert a long to a String is by appending it to double quotes, but for complex output where a long must be embedded in a Java String, use the printf or String.fomat method.

Compare the JShell program below where the plus operator is first used to add a long inside a String, while the printf option is used second.

// long to String conversion with printf
long longToConvert = 90210L;
String longAsString = "";

System.out.println("The long is " + longToConvert + " now in the String");
System.out.printf("The long is %d now in the String", longToConvert);

The use of printf makes embedding primitive types like a long in a String much easier.

The conversion of a long to a String with the plus operator will work with any of the 8 Java primitive types.