Print a Heart Shape in Java with a Single Stream Expression

This short tutorial shows how to create a heart‑shaped output in a Java console using only one line of code powered by the Stream API. The approach combines two nested IntStream ranges, a mathematical equation that defines the heart curve, and conditional logic to print either a character from the word "love" or a space.

IntStream.range(-15, 15)
    .map(y -> -y)
    .forEach(y -> IntStream.range(-30, 30).forEach(x -> System.out.print(
        Math.pow(Math.pow(x * 0.05, 2) + Math.pow(y * 0.1, 2) - 1, 3)
        - Math.pow(x * 0.05, 2) * Math.pow(y * 0.1, 3) <= 0
            ? "love".charAt(Math.abs((y - x) % 4))
            : " " + (x == 29 ? "
" : "")
    )));

The expression works as follows:

Outer stream : IntStream.range(-15, 15).map(y -> -y) iterates over the vertical coordinate y from 15 down to -15.

Inner stream : For each y, IntStream.range(-30, 30) iterates over the horizontal coordinate x from -30 to 29.

Heart formula : The condition

Math.pow(Math.pow(x * 0.05, 2) + Math.pow(y * 0.1, 2) - 1, 3) - Math.pow(x * 0.05, 2) * Math.pow(y * 0.1, 3) <= 0

evaluates whether the point ( x, y) lies inside the heart shape.

Character selection : If the point is inside the shape, a character from the string "love" is chosen based on Math.abs((y - x) % 4), creating a patterned fill. Otherwise a space is printed, and a newline is added at the end of each line when x == 29.

Running the program prints a heart made of the letters l, o, v, e in the console, as shown in the accompanying image.