JavaScript Examples

Dave Braunschweig

Arrays

// This program demonstrates array processing, including:
// display, total, max, min, parallel arrays, sort,
// fixed arrays, dynamic arrays, and multidimensional arrays.

main()

function main() {
    var names = ['Lisa', 'Michael', 'Ashley', 'Jacob', 'Emily'];
    var ages = [49, 48, 26, 19, 16];

    displayArray(names);
    displayArray(ages);

    var total = sum(ages);
    var maximum = max(ages);
    var minimum = min(ages);

    output('total: ' + total);
    output('maximum: ' + maximum);
    output('minimum: ' + minimum);

    displayParallel(names, ages);

    ages.sort();
    displayArray(ages);

    fixedArray();
    dynamicArray();
    displayMultidimensional();
}

function displayArray(array) {
    for (var index = 0; index < array.length; index++) {
        output('array[' + index + '] = ' + array[index]);
    }
}

function sum(array) {
    var total = 0;
    for (var index = 0; index < array.length; index++) {
        total += array[index];
    }
    return total;
}

function max(array) {
    var maximum = array[0];
    for (var index = 1; index < array.length; index++) {
        if (maximum < array[index]) {
            maximum = array[index];
        }
    }
    return maximum;
}

function min(array) {
    var minimum = array[0];
    for (var index = 1; index < array.length; index++) {
        if (minimum > array[index]) {
            minimum = array[index];
        }
    }
    return minimum;
}

function displayParallel(names, ages) {
    for (var index = 0; index < names.length; index++) {
        output(names[index] + ' is ' + ages[index] + ' years old');
    }
}

function fixedArray() {
    var array = new Array(5);

    for (var index = 0; index < array.length; index++) {
        var number = Math.floor(Math.random() * 100);
        array[index] = number;
    }
    displayArray(array);
}

function dynamicArray() {
    var array = [];

    for (var index = 0; index < 5; index++) {
        var number = Math.floor(Math.random() * 100);
        array.push(number);
    }
    displayArray(array);
}

function displayMultidimensional() {
    var game = [
        ['X', 'O', 'X'], 
        ['O', 'O', 'O'], 
        ['X', 'O', 'X'] ];

    for (var row = 0; row < 3; row++) {
        var line = '';
        for (var column = 0; column < 3; column++) {
            line += game[row][column];
            if (column < 2) {
                line += ' | ';
            }
        }
        output(line);
    }
}

function output(text) {
  if (typeof document === 'object') {
    document.write(text);
  } 
  else if (typeof console === 'object') {
    console.log(text);
  } 
  else {
    print(text);
  }
}

Output

array[0] = Lisa
array[1] = Michael
array[2] = Ashley
array[3] = Jacob
array[4] = Emily
array[0] = 49
array[1] = 48
array[2] = 26
array[3] = 19
array[4] = 16
total: 158
maximum: 49
minimum: 16
Lisa is 49 years old
Michael is 48 years old
Ashley is 26 years old
Jacob is 19 years old
Emily is 16 years old
array[0] = 16
array[1] = 19
array[2] = 26
array[3] = 48
array[4] = 49
array[0] = 55
array[1] = 4
array[2] = 46
array[3] = 88
array[4] = 49
array[0] = 28
array[1] = 95
array[2] = 13
array[3] = 60
array[4] = 60
X | O | X
O | O | O
X | O | X

References

License

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Programming Fundamentals Copyright © 2018 by Dave Braunschweig is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License, except where otherwise noted.

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