30 Answers · 1) The push() method adds one or more elements to the end of an array and returns the new length of the array. · 2) The unshift() method adds one or ... ... <看更多>
The push() method allows you to add one or more elements to the end of the array. The push() method returns the value of the length property that specifies the ... ... <看更多>
Basically after reading over the code, I interpret that the conditional (i.e. !obj[key].push ) checks if the value at the given key is not an array. ... <看更多>
