javascript - 在稀疏 javascript 数组中查找最大值

Question

是否有正确的方法来查找具有未定义值的稀疏数组的最大值？

谢谢

var testArr=[undefined,undefined,undefined,3,4,5,6,7];
console.log('max value with undefined is ',(Math.max.apply(null,testArr)));

// max value with undefined is NaN

console.log('max with arr.max()',testArr.max());    

// Error: testArr.max is not a function     

testArr=[null,null,null,3,4,5,6,7];
console.log('max value with null is ',(Math.max.apply(null,testArr)));

// max value with null is 7

如果有内置方法，我不想这样做。

Answer 1

testArr.reduce(function(a,b){
  if (isNaN(a) || a === null || a === '') a = -Infinity;
  if (isNaN(b) || b === null || b === '') b = -Infinity;
  return Math.max(a,b)
}, -Infinity);