Develop Reference

javascript pyramid within array

I need my output to look like this:
The best I could achieve was that:
Here is my code:
let pyramidComplete = (rows) => {
let array = [];
let str = '';
for (let i = 1; i <= rows; i++) {
//Add the white space to the left
for (let k = 1; k <= (rows - i); k++) {
str += ' ';
}
//Add the '*' for each row
for (let j = 0; j != (2 * i - 1); j++) {
str += "#".repeat(2 * i - 1);
}
//Add the white space to the right
for (let k = i + 1; k <= rows; k++) {
str += ' ';
}
//Print the pyramid pattern for each row
array.push(str)
str = '';
}
}
pyramidComplete(5);
I thought of assembling a line per loop and then, pushing it into an array but, I can't get the desired result.

The logic is fairly direct: for each row, the number of whitespaces is n - i - 1 where i is the row number. The number of # per row is i + 1. You can produce these substrings using String#repeat. Concatenate the two chunks together per line and use the index argument to Array#map's callback to produce each row.
const pyramid = n => Array(n).fill().map((_, i) =>
" ".repeat(n - i - 1) + "#".repeat(i + 1)
);
console.log(pyramid(5));
If the functions used here are incomprehensible, this can be simplified to use rudimentary language features as follows. It's similar to your approach, but the counts for each character per row are different, I iterate from 0 < n rather than 1 <= n and str should be scoped to the outer loop block.
function pyramid (n) {
var result = [];
for (var i = 0; i < n; i++) {
var line = "";
for (var j = 0; j < n - i - 1; j++) {
line += " ";
}
for (var j = 0; j < i + 1; j++) {
line += "#";
}
result.push(line);
}
return result;
}
console.log(pyramid(5));
If you need a true pyramid (which your current output seems to be shooting for, contrary to the expected output):
const pyramid = n => Array(n).fill().map((_, i) => {
const size = i * 2 + 1;
const pad = n - size / 2;
return " ".repeat(pad) + "#".repeat(size) + " ".repeat(pad);
});
console.log(pyramid(5));

I think you want to do this:
let doc, htm, bod, nav, M, I, mobile, S, Q, CharPyr; // for use on other loads
addEventListener('load', ()=>{
doc = document; htm = doc.documentElement; bod = doc.body; nav = navigator; M = tag=>doc.createElement(tag); I = id=>doc.getElementById(id);
mobile = nav.userAgent.match(/Mobi/i) ? true : false;
S = (selector, within)=>{
var w = within || doc;
return w.querySelector(selector);
}
Q = (selector, within)=>{
var w = within || doc;
return w.querySelectorAll(selector);
}
CharPyr = function(char = '#', className = 'pyr'){
this.char = char; this.className = className;
this.build = (height = 9)=>{
const p = M('div');
p.className = this.className;
for(let i=0,c=this.char,x=c,d; i<height; i++){
d = M('div'); d.textContent = x; p.appendChild(d); x += c;
}
return p;
}
}
// magic happens here
const out1 = I('out1'), out2 = I('out2'), out3 = I('out3'), pyr = new CharPyr;
out1.appendChild(pyr.build(5)); out2.appendChild(pyr.build(7)); out3.appendChild(pyr.build());
}); // end load
*{
box-sizing:border-box;
}
.out{
margin-bottom:7px;
}
.pyr>div{
color:#070; text-align:center;
}
<div class='out' id='out1'></div>
<div class='out' id='out2'></div>
<div class='out' id='out3'></div>

Building a JavaScript grid with odd and even characters using two loops

This is my first question on StackOverflow.
I have to build gridGenerator(num). If num is 3, it would look like this:
#_#
_#_
#_#
If num is 4, it would look like this:
#_#_
_#_#
#_#_
_#_#
I was able to solve it for odd numbers, but struggle to adjust it to even numbers.
function gridGenerator(num) {
var grid = '';
var row = '';
for (var i = 0; i < num; i++) {
for (var j = 0; j < num; j++) {
if (row.length % 2) {
row += '_';
} else {
row += '#';
}
}
grid += row.slice(-num) + '\n';
}
return grid;
}
console.log(gridGenerator(3));
Need a hint how to solve it for 2, 4, and other even numbers. Thank you!

Try this
if ((i+j) % 2)
function gridGenerator(num) {
var grid = '';
var row = '';
for (var i = 0; i < num; i++) {
for (var j = 0; j < num; j++) {
if ((i+j) % 2) {
row += '_';
} else {
row += '#';
}
}
grid += row.slice(-num) + '\n';
}
return grid;
}
console.log(gridGenerator(4));

You can use the condition num % 2 to determine if a number is even or odd. I would use two loops like you are doing. Make your character addition based on the even / odd state of the row and column. At the end of each row insert the line break.
EDIT: Here you go.
function generateGrid( num ) {
let i, j, grid = "";
for ( i = 0; i < num; i++ ) {
for ( j = 0; j < num; j++ ) {
if ( ( i + j ) % 2 ) {
grid += "_";
} else {
grid += "#";
}
}
grid += "\n";
}
return grid;
}
var grid = generateGrid( 4 );
console.log( grid );

function gridGen(num) {
var even = '';
for (var i = 0; i< num ; i++)
even += (i%2) ? '_' : '#';
odd = even.substring(1) + (num%2 ? '_' : '#');
var out = '';
for (var i = 0; i< num ; i++)
out += ((i%2) ? odd : even) + '\n';
return out;
}
console.log('Even Case');
console.log( gridGen(8));
console.log('Odd Case');
console.log( gridGen(7));
If you are looking for another approach + efficiency try this

Pyramide of Stars Javascript

How could I create Pyramide of Stars that increase every row by 2 like that:
*
* * *
* * * * *
* * * * * * *
My currently code:
for (var x = 0; x < 5; x++) {
for (var y = 0; y <= x; y = y + 1) {
document.write(" * ");
}
document.write("<br>");
}

It's possible just to increment in your loop by 2.
for(var i = 1; i < 20; i += 2) {
console.log( Array(i).fill('*').join(' ') );
}
Otherwise just multiply inside your loop
for(var i = 0; i < 10; i++) {
console.log( Array(i*2 + 1).fill('*').join(' ') );
}
You may also need to polyfill Array.fill depending on your target.

Other answers recreate the entire row each time. This solution just extends the row each time to have another star.
function pyramid(n) {
let result = '', str = '', add = '*';
for (var i = 0; i < n; i++) {
str += add;
add = ' *';
if (!(i % 2)) result += str + '\n';
}
return result;
}
console.log(pyramid(5));

You can do like this.
function generate() {
var totalNumberofRows = 5;
var output="";
for (var i = 1; i <= totalNumberofRows; i++) {
for (var j = 1; j <= i; j++) {
if(j==1)
output+="*";
else
output+=" "+ "*" + " "+ "*";
}
console.log(output);
output="";
}
}
generate()

Hope so this is also beneficial for you....
$(document).ready(function () {
var NumberofRows = 5,arr;
for (var i = 1; i <= NumberofRows; i++) {
pyramid = [];
for (var j = 1; j <= i; j++) {
pyramid.push('*');
}
console.log(pyramid.join(" ") + "\n");
}
});
``

Create range of letters and numbers

I'm creating a form where users can input a range. They are allowed to input letters and numbers. Some sample input:
From: AA01
To: AZ02
Which should result in:
AA01
AA02
AB01
AB02
And so on, till AZ02
And:
From: BC01
To: DE01
Should result in:
BC01
BD01
BE01
CC01
CD01
CE01
Etc
I managed to get it working for the input A01 to D10 (for example)
jsFiddle
However, i can't get it to work with multiple letters.
JS code:
var $from = $('input[name="from"]');
var $to = $('input[name="to"]');
var $quantity = $('input[name="quantity"]');
var $rangeList = $('.rangeList');
var $leadingzeros = $('input[name="leadingzeros"]');
$from.on('keyup blur', function () {
$(this).val($(this).val().replace(/[^a-zA-Z0-9]/g, ''));
updateQuantity();
});
$to.on('keyup blur', function () {
$(this).val($(this).val().replace(/[^a-zA-Z0-9]/g, ''));
updateQuantity();
});
$leadingzeros.on('click', function () {
updateQuantity();
});
function updateQuantity() {
var x = parseInt($from.val().match(/\d+/));
var y = parseInt($to.val().match(/\d+/));
var xl = $from.val().match(/[a-zA-Z]+/);
var yl = $to.val().match(/[a-zA-Z]+/);
var result = new Array();
if (xl != null && yl != null && xl[0].length > 0 && yl[0].length > 0) {
xl = xl[0].toUpperCase();
yl = yl[0].toUpperCase();
$rangeList.html('');
var a = yl.charCodeAt(0) - xl.charCodeAt(0);
for (var i = 0; i <= a; i++) {
if (!isNaN(x) && !isNaN(y)) {
if (x <= y) {
var z = (y - x) + 1;
$quantity.val(z * (a + 1));
$rangeList.html('');
for (var b = z; b > 0; b--) {
var c = ((y - b) + 1);
if ($leadingzeros.prop('checked')) {
c = leadingZeroes(c, y.toString().length);
}
result.push(String.fromCharCode(65 + i) + c);
}
} else {
$rangeList.html('');
$quantity.val(0);
}
} else {
$rangeList.html('');
$quantity.val(0);
}
}
} else if (!isNaN(x) && !isNaN(y)) {
if (x < y) {
var z = (y - x) + 1;
$quantity.val(z);
$rangeList.html('');
for (var i = z; i > 0; i--) {
var c = (y - i) + 1;
if ($leadingzeros.prop('checked')) {
c = leadingZeroes(c, y.toString().length);
}
result.push(c);
}
} else {
$rangeList.html('');
$quantity.val(0);
}
} else {
$rangeList.html('');
$quantity.val(0);
}
$rangeList.html('');
for (var i = 0; i < result.length; i++) {
$rangeList.append(result[i] + '<br />');
}
}
function leadingZeroes(number, size) {
number = number.toString();
while (number.length < size) number = "0" + number;
return number;
}

This is perfect for a recursive algorithm:
function createRange(from, to) {
if (from.length === 0) {
return [ "" ];
}
var result = [];
var innerRange = createRange(from.substring(1), to.substring(1));
for (var i = from.charCodeAt(0); i <= to.charCodeAt(0); i++) {
for (var j = 0; j < innerRange.length; j++) {
result.push(String.fromCharCode(i) + innerRange[j]);
}
}
return result;
}
Called as follows:
createRange('BC01', 'DE02'); // Generates an array containing all values expected
EDIT: Amended function below to match new test case (much more messy, however, involving lots of type coercion between strings and integers).
function prefixZeroes(value, digits) {
var result = '';
value = value.toString();
for (var i = 0; i < digits - value.length; i++) {
result += '0';
}
return result + value;
}
function createRange(from, to) {
if (from.length === 0) {
return [ "" ];
}
var result = [];
if (from.charCodeAt(0) < 65) {
fromInt = parseInt(from);
toInt = parseInt(to);
length = toInt.toString().length;
var innerRange = createRange(from.substring(length), to.substring(length));
for (var i = fromInt; i <= toInt; i++) {
for (var j = 0; j < innerRange.length; j++) {
result.push(prefixZeroes(i, length) + innerRange[j]);
}
}
} else {
var innerRange = createRange(from.substring(1), to.substring(1));
for (var i = from.charCodeAt(0); i <= to.charCodeAt(0); i++) {
for (var j = 0; j < innerRange.length; j++) {
result.push(String.fromCharCode(i) + innerRange[j]);
}
}
}
return result;
}

Please note that because of your strict logic in how the value increments this method requires exactly 4 characters (2 letters followed by 2 numbers) to work. Also, this might not be as efficient/tidy as it can be but it took some tinkering to meet your logic requirements.
function generate(start, end) {
var results = [];
//break out the start/end letters/numbers so that we can increment them seperately
var startLetters = start[0] + start[1];
var endLetters = end[0] + end[1];
var startNumber = Number(start[2] + start[3]);
var endNumber = Number(end[2] + end[3]);
//store the start letter/number so we no which value to reset the counter to when a maximum boundry in reached
var resetLetter = startLetters[1];
var resetNumber = startNumber;
//add first result as we will always have at least one
results.push(startLetters + (startNumber < 10 ? "0" + startNumber : "" + startNumber));
//maximum while loops for saefty, increase if needed
var whileSafety = 10000;
while (true) {
//safety check to ensure while loop doesn't go infinite
whileSafety--;
if (whileSafety == 0) break;
//check if we have reached the maximum value, if so stop the loop (break)
if (startNumber == endNumber && startLetters == endLetters) break;
//check if we have reached the maximum number. If so, and the letters limit is not reached
//then reset the number and increment the letters by 1
if (startNumber == endNumber && startLetters != endLetters) {
//reset the number counter
startNumber = resetNumber;
//if the second letter is at the limit then reset it and increment the first letter,
//otherwise increment the second letter and continue
if (startLetters[1] == endLetters[1]) {
startLetters = '' + String.fromCharCode(startLetters.charCodeAt(0) + 1) + resetLetter;
} else {
startLetters = startLetters[0] + String.fromCharCode(startLetters.charCodeAt(1) + 1);
}
} else {
//number limit not reached so just increment the number counter
startNumber++;
}
//add the next sequential value to the array
results.push(startLetters + (startNumber < 10 ? "0" + startNumber : "" + startNumber));
}
return results;
}
var results = generate("BC01", "DE01");
console.log(results);
Here is a working example, which uses your second test case

Using #Phylogenesis' code, i managed to achieve my goal.
jsFiddle demo
function updateQuantity() {
var x = parseInt($from.val().match(/\d+/));
var y = parseInt($to.val().match(/\d+/));
var xl = $from.val().match(/[a-zA-Z]+/);
var yl = $to.val().match(/[a-zA-Z]+/);
var result = new Array();
var r = createRange(xl[0], yl[0]);
var z = (y - x) + 1;
if (x <= y) {
for (var j = 0; j < r.length; j++) {
var letters = r[j];
for (var i = z; i > 0; i--) {
var c = (y - i) + 1;
if ($leadingzeros.prop('checked')) {
c = leadingZeroes(c, y.toString().length);
}
if (i == z) {
r[j] = letters + c + '<br />';
} else {
j++;
r.splice(j, 0, letters + c + '<br />');
}
}
}
} else {
for (var i = 0; i < r.length; i++) {
r[i] += '<br />';
}
}
$quantity.val(r.length);
$rangeList.html('');
for (var i = 0; i < r.length; i++) {
$rangeList.append(r[i]);
}
}
This works for unlimited letters and numbers, as long as the letters are first.
Thanks for your help!

What I do in javascript to get my required result?

Here is my javascript code
for (var i = 1; i <= _MAXPAGECOUNT - 2; i++) {
e = document.getElementsByName("q" + i + "[]");
for (var j = 0; j <= e.length - 1; j++) {
if (e[j].checked) {
result = result + "," + i + ":" + e[j].value;
// break;
}
}}
The problem is this, it shows result like this 1:2,1:3,1:4,2:3,2:4,2:5
here in code i means question number and j means answer number, but I want to result as like this 1:2,3,4 ; 2:3,4,5

Try this
for (var i = 1; i <= _MAXPAGECOUNT - 2; i++) {
result = result+i+":";
e = document.getElementsByName("q" + i + "[]");
for (var j = 0; j <= e.length - 1; j++) {
if (e[j].checked) {
result = result + e[j].value;
// break;
}
}
if(i<_MAXPAGECOUNT - 2)
{
result = result+" ; ";
}
}