Count number of chars in string

This example will find the number of occurrences of a character in a string using groovy. We will use the string count method, findAll passing a closure and convert the string to a char array passing in the ASCII value to the count method. A comparable example we demonstrate how to count instances of a character in string using java, java 8, guava, apache commons and spring framework.

Count chars in string

void count_chars_in_string() {

    def lombardiQuote = "The achievements of an organization are " + 
            "the results of the combined effort of each individual."

    assert 11, lombardiQuote.count("e")

Find all chars in string

If you didn't like the ease of count above, you could filter then find the size of the resulting collection.

void count_chars_with_filter_string () {
    def lombardiQuote = "Individual commitment to a group effort – that "
        + "is what makes a team work, a company work, a society work, "
        + "a civilization work."
    assert 5, lombardiQuote.findAll({it -> it == "e"}).size()

Find chars by ASCII

void count_chars_in_string_chars () {
    def lombardiQuote = "People who work together will win, whether it be against "
        "complex football defenses, or the problems of modern society."
    assert 7, lombardiQuote.getChars().count(101)