Iterative conditional removal of object property using 'for..in' and 'if' [duplicate]

问题

This question already has answers here:

Dynamically access object property using variable (13 answers)

Closed 2 years ago.

function removeNumbersLargerThan(num, obj) {
  for (var key in obj) {
    if (!isNaN(obj[key]) && obj[key] > num) {
      delete obj.key;
    }
  }
  return obj;
}
var obj = {
  a: 8,
  b: 2,
  c: 'montana'
}
removeNumbersLargerThan(5, obj);
console.log(obj); // Should be {b: 2, c: 'montana'}

The function should remove any property that meets the 'if' condition inside the 'for' loop, but it doesn't.

回答1:

You miss the square brackets, while defining the object key to delete.

function removeNumbersLargerThan(num, obj) {
  for (var key in obj) {
    if (!isNaN(obj[key]) && obj[key] > num) {
      delete obj[key];
    }
  }
  return obj;
}
var obj = {
  a: 8,
  b: 2,
  c: 'montana'
}
removeNumbersLargerThan(5, obj);
console.log(obj); // Should be {b: 2, c: 'montana'}

回答2:

You should replace delete obj.key; with delete obj[key];

来源：https://stackoverflow.com/questions/43615295/iterative-conditional-removal-of-object-property-using-for-in-and-if