This post goes over how to use alert, confirm, and prompt with Google Sheets Macros.

• Alert
• Confirm
• Prompt

Alert

Open a dialog box with an OK button:

SpreadsheetApp.getUi().alert('Message');

See the documentation.

Confirm

Open a dialog box with Yes and No buttons:

const ui = SpreadsheetApp.getUi();
const response = ui.alert('Title', 'Message', ui.ButtonSet.YES_NO);

switch (response) {
  case ui.Button.YES:
    console.log('Yes');
    break;
  case ui.Button.NO:
    console.log('No');
    break;
  default:
    console.log('Clicked outside');
    break;
}

SpreadsheetApp.getActive().toast(response);

See the documentation.

Prompt

Open an input dialog box with an OK button:

const ui = SpreadsheetApp.getUi();
const response = ui.prompt('Input:');

if (response.getSelectedButton() === ui.Button.OK) {
  const text = response.getResponseText();
  console.log(text);
  SpreadsheetApp.getActive().toast(text);
}

Open an input dialog box with Yes, No, and Cancel buttons:

const ui = SpreadsheetApp.getUi();
const response = ui.prompt('Input:');
const text = response.getResponseText();

switch (response.getSelectedButton()) {
  case ui.Button.YES:
    console.log('Yes', text);
    break;
  case ui.Button.NO:
    console.log('No', text);
    break;
  case ui.Button.CANCEL:
    console.log('Cancel', text);
    break;
  default:
    console.log('Clicked outside', text);
    break;
}

SpreadsheetApp.getActive().toast(text);

See the documentation.

Alternatively, there’s the deprecated Browser.inputBox and Browser.msgBox, which are no longer recommended.