6.7: The break Statement

The break statement is used to exit a loop immediately. When MATLAB reaches break, it leaves the loop even if the loop condition would otherwise continue.

Example: Password Check

Suppose we want to keep asking a user for a password until the correct password is entered. We can create an infinite loop using while true, and then use break to exit the loop when the password is correct.

correctPass = 'abc';

while true
    password = input('Please enter your password: ', 's');
    if strcmp(password, correctPass)
        break;
    end
end

disp('Welcome!');

Notice that this example uses strcmp to compare character vectors. In MATLAB, text comparisons should generally be done with functions such as strcmp or strcmpi, not with ==, especially when comparing words or phrases.

Important Correction

When comparing text such as passwords, use strcmp(password, correctPass). Do not rely on password == correctPass for general text comparisons.

When Should You Use break?

The break statement is useful when you want the loop to stop as soon as a certain event happens. For example, you might use break when:

• a search value is found,
• a correct password is entered,
• a user chooses to quit, or
• continuing the loop is no longer necessary.