Loop Over Array in Javascript

This question already has an answer here:

For-each over an array in JavaScript? 23 answers

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I'm trying to loop over the MoveParts in javascript like this:

for (var movePart in moveResult.MoveParts) {
    console.log(movePart.From);
};

I always get undefined instead of the actual value.

Don't use for-in to loop through arrays, that's not what it's for. for-in is for looping through object properties. This answer shows various ways to loop through arrays.

The reason your for-in didn't work is that movePart is the key, not the actual entry, so if you were using an object (not an array!) you would have used moveResult.MoveParts[movePart].From .

Your forEach version only failed because:

It's forEach , not foreach . Capitalization matters in JavaScript.

You were missing the closing ) on the function call.

The answer linked above has full examples of forEach and others, but here's how yours should have looked:

    moveResult.MoveParts.forEach(function (movePart) {
    // Capital E -----------^
        console.log(movePart.From);
    });
//   ^---- closing )

---

尝试

moveResult.MoveParts.map(function (movePart) {
    console.log(movePart.From);
};

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