JavaScript Event Handling and Evaluation

Front

What does the line 'let scrn = document.getElementById("screen");' do?

Back

It selects the HTML element with the id 'screen' and assigns it to the variable 'scrn'.

Front

What is the purpose of 'currentvalue' in the code?

Back

It stores the current value being displayed or calculated.

Front

What does 'document.querySelectorAll("td").forEach(cell => {' do?

Back

It selects all 'td' elements in the document and iterates over them, allowing for event listeners to be added to each cell.

Front

What happens when a cell with the text 'C' is clicked?

Back

The 'currentvalue' is reset to an empty string.

Front

What does the line 'currentvalue = eval(currentvalue).toString();' do?

Back

It evaluates the expression stored in 'currentvalue' and converts the result to a string.

Front

What is the effect of clicking a cell that contains a number or operator?

Back

The clicked value is appended to 'currentvalue'.

Front

What does 'scrn.textContent = currentvalue;' accomplish?

Back

It updates the text content of the 'screen' element with the current value.