Javascript Practice 60: JS Hero - Array of arrays

 

Question: 

Write a function flat that flattens a two-dimensional array with 3 entries.

let row1 = [4, 9, 2];

let row2 = [3, 5, 7];

let row3 = [8, 1, 6];

let loshu = [row1, row2, row3];

Example: flat(loshu) should return [4, 9, 2, 3, 5, 7, 8, 1, 6]. Thereby loshu is the magic square from the example above.

Answer: 

function flat (array) {

let entryA = array[0]; 

let entryB = array[1]; 

let entryC = array[2]; 

let finalD = entryA.concat(entryB, entryC);

return finalD;

};

> declare a function flat

> it has 1 parameter array

> we know that we need to flatten a two dimensional array which has 3 entries / arrays

> an array that contains an array is called a two dimensional array

> we declare 3 variables that access the three entries / arrays within the 2D array

> we then concat all three arrays using the concat () method and store the output in another variable finalD

> we return the finalD variable to get our single flattened array