array drills
function makeList(item1, item2, item3) {
return [item1, item2, item3];
}
/* From here down, you are not expected to
understand.... for now :)
Nothing to see here!
*/
// tests
function testMakeList() {
const items = ['prime rib', 'fried goat cheese salad', 'fish tacos'];
const result = makeList(items[0], items[1], items[2]);
if (
result &&
result.length &&
items.length === result.length &&
items.every(function(item) {
return result.indexOf(item) > -1;
})
) {
console.log('SUCCESS: `makeList` works!');
} else {
console.error('FAILURE: `makeList` is not working');
}
}
testMakeList();
function addToList(list, item) {
list.push(item);
return list;
}
/* From here down, you are not expected to
understand.... for now :)
Nothing to see here!
*/
// tests
function testAddToList() {
const input1 = ['red', 'blue', 'green'];
const input2 = 'pink';
const expected = ['red', 'blue', 'green', 'pink'];
const result = addToList(input1, input2);
if (
result &&
result.length &&
expected.length === result.length &&
expected.every(function(item) {
return result.indexOf(item) > -1;
})
) {
console.log('SUCCESS: `addToList` works!');
} else {
console.error('FAILURE: `addToList` is not working');
}
}
testAddToList();
function accessFirstItem(array) {
return array[0];
}
function accessThirdItem(array) {
return array[2];
}
/* From here down, you are not expected to
understand.... for now :)
Nothing to see here!
*/
// tests
function testFunctionWorks(fn, input, expected) {
if (fn(input) === expected) {
console.log(`SUCCESS: "${fn.name}" works on [${input}]`);
return true;
} else {
console.log(
`FAILURE: ${fn.name}([${input}]) should be ${expected} but was ${fn(
input
)}`
);
return false;
}
}
function runTests() {
var list = [1, 4, 9, 16, 25];
var item1 = 1;
var item2 = 9;
var testResults = [
testFunctionWorks(accessFirstItem, list, item1),
testFunctionWorks(accessThirdItem, list, item2),
];
var numPassing = testResults.filter(function(result) {
return result;
}).length;
console.log(numPassing + ' out of ' + testResults.length + ' tests passing.');
}
runTests();
function findLength(array) {
return array.length;
}
function accessLastItem(array) {
return array.pop();
}
/* From here down, you are not expected to
understand.... for now :)
Nothing to see here!
*/
// tests
function testFunctionWorks(fn, input, expected) {
if (fn(input) === expected) {
console.log('SUCCESS: `' + fn.name + '` works on `[' + input + ']`');
return true;
} else {
console.error(
'FAILURE: `' +
fn.name +
'([' +
input +
'])` should be ' +
expected +
' but was ' +
fn(input)
);
return false;
}
}
function runTests() {
const list = [1, 4, 9, 16, 25];
const originalList = [1, 4, 9, 16, 25];
const length = 5;
const lastItem = 25;
const testResults = [
testFunctionWorks(findLength, list, length),
testFunctionWorks(accessLastItem, list, lastItem),
];
const numPassing = testResults.filter(function(result) {
return result;
}).length;
console.log(numPassing + ' out of ' + testResults.length + ' tests passing.');
}
runTests();
function firstFourItems(array) {
return array.slice(0,4);
}
function lastThreeItems(array) {
const result2 = array.slice(-3);
console.log(result2);
return result2;
}
/* From here down, you are not expected to
understand.... for now :)
Nothing to see here!
*/
// tests
function testFunctionWorks(fn, input, expected) {
const result = fn(input);
if (
result &&
result.length === expected.length &&
result.every(function(item) {
return expected.indexOf(item) > -1;
})
) {
console.log('SUCCESS: `' + fn.name + '` works!');
return true;
} else {
console.error('FAILURE: `' + fn.name + '` is not working');
return false;
}
}
function runTests() {
const list = ['red bull', 'monster', 'amp', 'rockstar', 'full throttle'];
const result1 = ['red bull', 'monster', 'amp', 'rockstar'];
const result2 = ['amp', 'rockstar', 'full throttle'];
const testResults = [
testFunctionWorks(firstFourItems, list, result1),
testFunctionWorks(lastThreeItems, list, result2),
];
const numPassing = testResults.filter(function(result) {
return result;
}).length;
console.log(numPassing + ' out of ' + testResults.length + ' tests passing.');
}
runTests();
function minusLastItem(array) {
return array.slice(0,-1);
}
function copyFirstHalf(array) {
return array.slice(0, array.length/2);
}
/* From here down, you are not expected to
understand.... for now :)
Nothing to see here!
*/
// tests
function testFunctionWorks(fn, input, expected) {
const result = fn(input);
if (
result &&
result.length === expected.length &&
result.every(function(item) {
return expected.indexOf(item) > -1;
})
) {
console.log('SUCCESS: `' + fn.name + '` works!');
return true;
} else {
console.error('FAILURE: `' + fn.name + '` is not working');
return false;
}
}
function runTests() {
const list = [
'red bull',
'monster',
'amp',
'rockstar',
'full throttle',
'kickstart',
];
const result1 = ['red bull', 'monster', 'amp', 'rockstar', 'full throttle'];
const result2 = ['red bull', 'monster', 'amp'];
const list2 = ['lions', 'tigers', 'bears'];
const result3 = ['lions'];
const testResults = [
testFunctionWorks(minusLastItem, list, result1),
testFunctionWorks(copyFirstHalf, list, result2),
testFunctionWorks(copyFirstHalf, list2, result3)
];
const numPassing = testResults.filter(function(result) {
return result;
}).length;
console.log(numPassing + ' out of ' + testResults.length + ' tests passing.');
}
runTests();
function squares(array) {
return array.map(array => array ** 2);
}
/* From here down, you are not expected to
understand.... for now :)
Nothing to see here!
*/
// tests
function testFunctionWorks(fn, input, expected) {
const result = fn(input);
if (
result &&
result.length === expected.length &&
result.every(function(item) {
return expected.indexOf(item) > -1;
})
) {
console.log('SUCCESS: `' + fn.name + '` works!');
return true;
} else {
console.error(
'FAILURE: `' +
fn.name +
'([' +
input +
'])` should be ' +
expected +
' but was ' +
fn(input)
);
return false;
}
}
function runTests() {
const input1 = [1, 2, 3, 4, 5];
const result1 = [1, 4, 9, 16, 25];
const input2 = [2, 4, 6, 8];
const result2 = [4, 16, 36, 64];
const testResults = [
testFunctionWorks(squares, input1, result1),
testFunctionWorks(squares, input2, result2),
];
const numPassing = testResults.filter(function(result) {
return result;
}).length;
console.log(numPassing + ' out of ' + testResults.length + ' tests passing.');
}
runTests();
function greatestToLeast(array) {
return array.sort(function(a,b) {
return b-a;
})
}
/* From here down, you are not expected to
understand.... for now :)
Nothing to see here!
*/
// tests
function testFunctionWorks(fn, input, expected) {
const result = fn(input);
if (
result &&
result.length === expected.length &&
result.every(function(item, index) {
return index === 0 || result[index] < result[index - 1];
}) &&
result.every(function(item) {
return expected.indexOf(item) > -1;
})
) {
console.log('SUCCESS: `' + fn.name + '` works!');
return true;
} else {
console.error(
'FAILURE: `' +
fn.name +
'([' +
input +
'])` should be ' +
expected +
' but was ' +
fn(input)
);
return false;
}
}
function runTests() {
const input1 = [10, 3, 5, 22, 19];
const result1 = [22, 19, 10, 5, 3];
const input2 = [2, 4, 6, 8];
const result2 = [8, 6, 4, 2];
const testResults = [
testFunctionWorks(greatestToLeast, input1, result1),
testFunctionWorks(greatestToLeast, input2, result2),
];
const numPassing = testResults.filter(function(result) {
return result;
}).length;
console.log(numPassing + ' out of ' + testResults.length + ' tests passing.');
}
runTests();
function shortWords(array) {
return array.filter(string => string.length < 5);
}
/* From here down, you are not expected to
understand.... for now :)
Nothing to see here!
*/
// tests
function testFunctionWorks(fn, input, expected) {
const result = fn(input);
if (
result &&
result.length === expected.length &&
result.every(function(item) {
return expected.indexOf(item) > -1;
})
) {
console.log('SUCCESS: `' + fn.name + '` works!');
return true;
} else {
console.error(
'FAILURE: `' +
fn.name +
'([' +
input +
'])` should be ' +
expected +
' but was ' +
fn(input)
);
return false;
}
}
function runTests() {
const input1 = ['cat', 'oblivion', 'dog', 'patriarchy', 'blue', 'house'];
const result1 = ['cat', 'dog', 'blue'];
const input2 = ['rainbow', 'the', 'big', 'broom'];
const result2 = ['the', 'big'];
const testResults = [
testFunctionWorks(shortWords, input1, result1),
testFunctionWorks(shortWords, input2, result2),
];
const numPassing = testResults.filter(function(result) {
return result;
}).length;
console.log(numPassing + ' out of ' + testResults.length + ' tests passing.');
}
runTests();