Concatenate a two dimensional array

Question

I'm new and I need help to find the right solution for my function in java

function concatenateMatrix(matrix) {}
var stringMatrix = [
    ['H', 'e', 'l', 'l', 'o'],
    [' ', 'J', 'a', 'v', 'a'],
    ['W', 'o', 'r', 'l', 'd', '!']
];
var matrix = '';
newArray = [];
for (var i = 0; i < stringMatrix.length; i++) {
    for (var j = 0; j < stringMatrix[i].length; j++);
    newArray.push(stringMatrix);
    stringMatrix = '';
}
console.log(concatenateMatrix(stringMatrix))

It should be Hello , Java World! displayed.

What do I wrong? Thanks a lot

I have solved it, thanks a lot

for(var x in stringMatrix) {
if(stringMatrix[x] instanceof Array) {
    stringMatrix[x] = stringMatrix[x].join("");
}

} var concatenateMatrix = stringMatrix.join("");

return concatenateMatrix;

Answer 1

You can first flatten/merge the array elements and then join then with "" to show the full word like

[].concat.apply([], stringMatrix).join("")

 var stringMatrix = [ ['H','e','l','l','o'], [' ','J','a','v','a'], ['W','o','r','l','d','!'] ]; console.log([].concat.apply([], stringMatrix).join("")) 

Answer 2

function matrixMapper(matrix){
  var str = ''
  matrix.map(function(arr){
    str += arr.join('') + ' '
  })
console.log(str)
}

Basically iterate over the arrays in the matrix, join the subarrays and add them to your string

Answer 3

You can also use reduce() , concat() and join() method of array.

DEMO

 var arr= [ ['H','e','l','l','o'], [' ','J','a','v','a'], ['W','o','r','l','d','!'] ]; console.log(arr.reduce((r,v)=>r.concat(v),[]).join('')); 

 .as-console-wrapper { max-height: 100% !important; top: 0; } 

---

Using map()

 var arr= [ ['H','e','l','l','o'], [' ','J','a','v','a'], ['W','o','r','l','d','!'] ]; console.log(arr.map(v=>v.join('')).join('')); 

 .as-console-wrapper { max-height: 100% !important; top: 0; } 

Answer 4

Buddy, I think you are new to javaScript you can achieve your goal using single array only, don't need to use two loops and two array. I have checked your code write little bit code for you try to

 var stringMatrix = ['H','e','l','l','o',' ','J','a','v','a','W','o','r','l','d','!'];
        for(var i=0; i<stringMatrix.length; i++){    
            document.write(stringMatrix[i]);
        }

Answer 5

since everybody pointed out easier ways of doing that, but you have very concerning flaws in your code writing, here is a simple correction of your code :

function concatenateMatrix(matrix) {
    var stringMatrix = [
        ['H','e','l','l','o'],
        [' ','J','a','v','a'],
        ['W','o','r','l','d','!']
    ];
    var matrix = '';
    newArray = [];
    for(var i=0; i<stringMatrix.length; i++){
        for(var j=0; j<stringMatrix[i].length; j++){
            newArray.push(stringMatrix[i][j]);
        }
    }
    return newArray;
}
console.log(concatenateMatrix(stringMatrix));

you closed too early your curly braces, code with indentation so you can see theese problems, you missed the return value, you were adding stringMatrix instead of stringMatrix[i][j] , and you were clearing your stringMatrix every time in your i loop (maybe you wanted to clear stringMatrix[i] instead ?)

Answer 6

You can concat the arrays and then Join the final array with Join function of arrays.

var str=[]; 
for(var i=0;i<stringMatrix.length;i++){ 
  str = str.concat(stringMatrix[i]);
}
console.log(str.join(" "));