如何使声明不断重复，直到它成为真的？

Question

I want this statement to repeat itself until the condition is true, forgot the syntax to do so

let gradeAmount = Number(prompt('insert a number between 1 and 5'));
const grades = [];
if (gradeAmount >= 1 && gradeAmount <= 5) {
  for (let i = 0; i < gradeAmount; i++) {
    const grade = Number(prompt('insert the grade'));

    grades.push(grade);
  }
} else {
  alert('invalid number of grades, please insert again');
  gradeAmount = Number(prompt('insert a number between 1 and 5'));
}

Answer 1

A possible solution is to use do...while . This code will keep display alert('invalid number of grades, please insert again') and window.prompt until it meets you condition. Then it will window.prompt for user to enter the number.

 let gradeAmount = Number(prompt('insert a number between 1 and 5')); const grades = []; do{ alert('invalid number of grades, please insert again'); gradeAmount = Number(prompt('insert a number between 1 and 5')); } while(gradeAmount <= 1 && gradeAmount >= 5) for (let i = 0; i < gradeAmount; i++) { const grade = Number(prompt('insert the grade')); grades.push(grade); }