Given a 2D array, we have to convert it to a comma-separated values (CSV) string using JS.
Input: [ [ "a" , "b"] , [ "c" ,"d" ] ] Output: "a,b c,d" Input: [ [ "1", "2"] ["3", "4"] ["5", "6"] ] Output: "1,2 3,4 5,6"
To achieve this, we must know some array prototype functions which will be helpful in this regard:
Join function: The Array.prototype.join( ) function is used to join all the strings in an array with a character/string.
[ "a","b"].join( ",") will result in : "a,b"
Map function: The Array.prototype.map() returns a new array with the results of calling a function which we provide, on each element.
arr= ["a","b"] // Adding "c" to each element newArray = arr.map( item => item + "c") value of newArray = ["ac", "bc"]
Approach: We will use the map function and join function to combine each 1D row into a string with the separation of a comma. and then join all the individual strings with “\n”, using the join function.
Explanation: We first used the map function on the 2D array to traverse on each row, then we used the join function to join the array of elements in that row using a comma. Next, that map function returns an array of strings, which we join by using “\n”. Thus resulting in a CSV string.
Alternative Approach: We can even use for loops to traverse in the array, instead of a map.
Output: a,2 c,d