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[JS] math methods

取最小值​

Math.min( )
console.log(Math.min(2, 3, 1));
// Expected output: 1

console.log(Math.min(-2, -3, -1));
// Expected output: -3

const array1 = [2, 3, 1];

console.log(Math.min(...array1));
// Expected output: 1
// 最大值就改成Math.max()

無條件捨去​

Math.floor( )
// 無條件捨去
console.log(Math.floor(5.95));
// Expected output: 5
console.log(Math.floor(5.05));
// Expected output: 5

無條件進位​

Math.ceil( )
console.log(Math.ceil(7.004));
// Expected output: 8
console.log(Math.ceil(-7.004));
// Expected output: -7

四捨五入​

Math.round( )
console.log(Math.round(5.95), Math.round(5.5), Math.round(5.05));
// Expected output: 6 6 5

介於 0~1 隨機數​

Math.random( )
function getRandomInt(max) {
  return Math.floor(Math.random() * max);
}

console.log(getRandomInt(3));
// Expected output: 0, 1 or 2

console.log(getRandomInt(1));
// Expected output: 0

console.log(Math.random());
// Expected output: a number from 0 to <1

開根號​

Math.sqrt( )
function calcHypotenuse(a, b) {
  return Math.sqrt(a * a + b * b);
}

console.log(calcHypotenuse(3, 4));
// Expected output: 5

console.log(calcHypotenuse(5, 12));
// Expected output: 13

console.log(calcHypotenuse(0, 0));
// Expected output: 0

次方​

Math.pow( )
console.log(Math.pow(7, 3));
// Expected output: 343

console.log(Math.pow(4, 0.5));