How to combine two string in twig?

Question

I want to do something like this:

{% set c=a+b %}

Where a and b are strings.
How can I do it?

Answer 1

A clearer example for the {% block page %}...{% endblock %}:

{% block page %}
    {% set page = page | merge({
    "title"       : branchName,
    "description" : "This description has "~branchName~" as its title"
    }) %}
    {{ parent() }}
{% endblock %}

A clearer example for the {% block content %}...{% endblock %}:

{% block content %}
    This is just a sample string for {{ branchName }} that needs no concatenation
{% endblock %}