And the sons of Josiah were, the firstborn Johanan, the second Jehoiakim, the third Zedekiah, the fourth Shallum.
Zedekiah - is called the son of Josiah, cf. Jeremiah 1:3; Jeremiah 37:1, but, 2 Chronicles 36:19 he is described as the brother of Jehoiachin, who was the son of Jehoiachim, and consequently the grandson of Josiah. Words expressive of affinity or relationship are used with great latitude in the Hebrew.
Shallum. No king of this name is mentioned in the history of Josiah's sons (2 Kings 14:1-29; 2 Kings 23:1-37), but there is a notice of Shallum, the son of Josiah, Jeremiah 22:11, who reigned in the stead of his father, and who is generally supposed to be Jehoahaz, a younger son, here called the fourth of Josiah.