String class addition and multiplication operations

This page explains the String class addition and multiplication operations.

Addition

The String class addition operation (+) returns the concatenated String value:

import apysc as ap

ap.Stage()
string_1: ap.String = ap.String("Hello")
string_2: ap.String = string_1 + " World!"
assert string_2 == "Hello World!"
assert isinstance(string_2, ap.String)

Also, the += operator is supported:

import apysc as ap

ap.Stage()
string_1: ap.String = ap.String("Hello")
string_1 += " World!"
assert string_1 == "Hello World!"

A String value + Python built-in str operation is supported. Similarly, a String value + String value operation is also supported:

import apysc as ap

ap.Stage()
string_1: ap.String = ap.String("Hello")
string_2: ap.String = ap.String(" World!")
string_3: ap.String = string_1 + string_2
assert string_3 == "Hello World!"

But a Python built-in str + String value is not supported; for instance, the following code raises an error:

import apysc as ap

ap.Stage()
string_1: ap.String = ap.String(" World!")
string_2: ap.String = "Hello" + string_1

TypeError: must be str, not String

Multiplication

The String class multiplication operation (*) returns the repeated String value, same behaviors as the Python built-in str value:

import apysc as ap

ap.Stage()
string_1: ap.String = ap.String("Hello")
string_2: ap.String = string_1 * 3
assert string_2 == "HelloHelloHello"

The int or Int values are acceptable at the operation’s right-side value:

import apysc as ap

ap.Stage()
string_1: ap.String = ap.String("Hello")
int_1: ap.Int = ap.Int(3)
string_2: ap.String = string_1 * int_1
assert string_2 == "HelloHelloHello"