String class length property

This page explains the String class length property.

What property is this?

The length property returns the number of characters.

For example, the ABCDEF string returns 6, and the あいうえお string returns 5.

Basic usage

The length property returns an Int value as follows:

import apysc as ap

ap.Stage(
    stage_width=0,
    stage_height=0,
    background_color=ap.Color("#333"),
    stage_elem_id="stage",
)

string: ap.String = ap.String("ABCDEF")
length: ap.Int = string.length
ap.assert_equal(length, 6)

ap.save_overall_html(dest_dir_path="string_length_basic_usage_1/")

Notes of the emoji

This property returns an unexpected characters length when the string is an emoji character: since this property counts Unicode code points.

Most of the emoji characters behave as expected length, as follows:

import apysc as ap

ap.Stage(
    stage_width=0,
    stage_height=0,
    background_color=ap.Color("#333"),
    stage_elem_id="stage",
)
string: ap.String = ap.String("🎉")
ap.assert_equal(string.length, 1)

string = ap.String("🥳🌟🍻")
ap.assert_equal(string.length, 3)

ap.save_overall_html(dest_dir_path="string_length_notes_1/")

However, in some emojis that have multiple code points, this property returns an unexpected length of characters (this behavior is the same as the Python):

import apysc as ap

ap.Stage(
    stage_width=0,
    stage_height=0,
    background_color=ap.Color("#333"),
    stage_elem_id="stage",
)

assert len("👨‍👩‍👦") == 5

string: ap.String = ap.String("👨‍👩‍👦")
ap.assert_equal(string.length, 5)

ap.save_overall_html(dest_dir_path="string_length_notes_2/")

length property API

Note: the document build script generates and updates this API document section automatically. Maybe this section is duplicated compared with previous sections.

[Interface summary]

Get a character length (number).

[Returns]

  • characters_length: Int

    • A character length (number).

[Examples]

>>> import apysc as ap
>>> _ = ap.Stage()
>>> string: ap.String = ap.String("Hello")
>>> string.length
Int(5)