What is an example of irony in A Doll's House?

Irony plays a significant role in A Doll's House by Henrik Ibsen. 

There are several instances of dramatic irony, an example of irony often used in plays because it enables the audience to know more about what is happening than the character does. This device is frequently used to create suspense in a dramatic piece. 

In act 1, an example of dramatic irony occurs when Torvald thinks his wife is a spendthrift. She is,...

Irony plays a significant role in A Doll's House by Henrik Ibsen. 

There are several instances of dramatic irony, an example of irony often used in plays because it enables the audience to know more about what is happening than the character does. This device is frequently used to create suspense in a dramatic piece. 

In act 1, an example of dramatic irony occurs when Torvald thinks his wife is a spendthrift. She is, instead, working to repay the loan that she illegally procured for her husband's health. (They went to Italy where Torvald recovered his health after working so hard in earlier years.)  

Another example of dramatic irony occurs in act III. Torvald gallantly tells Nora that he will support her through anything. 

TORVALD. Do you know, Nora [Torvald whispers], I have often wished that you might be threatened by some great danger, so that I might risk my life's blood and everything for your sake?

However, after he learns of Nora having forged her father's signature to obtain the loan needed for them to go to Italy—where Torvald's health was restored—Torvald completely rejects Nora.

TORVALD. What a dreadful awakening! All these eight years. . . she, my pride and my joy—a hypocrite, a liar—oh worse! worse!—a criminal!. . . To go down so miserably, to be destroyed—all because of an irresponsible woman!. . . 
You'll go on living here, that goes without saying. But I won't let you bring up the children; I dare not trust you with them.

In act III, verbal irony, the saying of something that contradicts what one really means, occurs in a conversation between Torvald and Nora. After Torvald's name-calling and bitter words to Nora, Torvald then tells Nora that she must not pay any attention to the hard words he has used against her, Torvald says that he has "really. . . forgiven you." Nora replies with verbal irony, "I thank you for your forgiveness." She then goes out through a door into another room. Later, she leaves Torvald and the children.

In act II, there is an instance of situational irony, the discrepancy between expectation and what really happens. Nora wishes to help her friend Mrs. Linde, so she convinces her husband to fire Krogstad and give Mrs. Linde a job. However, this gesture of Nora's backfires on her as Krogstad then threatens to expose Nora's having committed forgery if he does not get reinstated in his lost position, a position he had until Mrs. Linde was given it.