Splicing a Javascript array from within the callback passed to forEach

Lets see why JavaScript behaves like this. According to the ECMAScript standard specification for Array.prototype.forEach,

when you delete an element at index 1, the element at index 2 becomes the element at index 1 and index 2 doesn’t exist for that object.

Now, JavaScript looks for element 2 in the object, which is not found, so it skips the function call.

That is why you see only a and b.


The actual way to do this, is to use Array.prototype.filter

var array = ["a", "b", "c"];

array = array.filter(function(currentChar) {
    console.log(currentChar);   // a, b, c on separate lines
    return currentChar !== "b";
});
console.log(array);             // [ 'a', 'c' ]

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