如何使声明不断重复，直到它成为真的？

Question

我希望这个语句重复自己直到条件为真，忘记了这样做的语法

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

一个可能的解决方案是使用do...while 。 此代码将一直显示alert('invalid number of grades, please insert again')和window.prompt直到满足您的条件。 然后它会 window.prompt 让用户输入数字。

 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); }