In Pride and Prejudice, one very large irony is that while Elizabeth was being dismissive toward Darcy and while she believed he was being mercilessly critical of her, he was actually falling in love with her and then, despite his understanding of superiority of position and wealth, he had no emotional or personal choice but to break down and (badly) propose marriage to her. Another irony is that while on holiday with her Aunt and Uncle Gardiner hoping to forget about Darcy, she encounters him at his own home, to which he has returned suddenly without notice. This led to another great irony in that Darcy became involved in searching for and saving Lydia, who, ironically wouldn't have been in danger if he had disclosed Wickham's true nature.
Foreshadowing appears in the encounter between Darcy and Wickham, which opens the gate to conflict and conflict resolution involving an uncomfortable alliance between the two men. Another instance of foreshadowing occurs when Darcy praises the virtues of a fine pair of eyes on the occasion of Elizabeth's journey to Bingley's estate to see Jane, who is stricken with illness, thus foreshadowing Darcy's growing love of Elizabeth.