Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
Looping
Search
John Nunemaker
PRO
September 24, 2009
Programming
0
8
Looping
John Nunemaker
PRO
September 24, 2009
Tweet
Share
More Decks by John Nunemaker
See All by John Nunemaker
Atom
jnunemaker
PRO
10
4.2k
MongoDB for Analytics
jnunemaker
PRO
11
840
Addicted to Stable
jnunemaker
PRO
32
2.5k
MongoDB for Analytics
jnunemaker
PRO
21
2.2k
MongoDB for Analytics
jnunemaker
PRO
16
30k
Why You Should Never Use an ORM
jnunemaker
PRO
55
9.2k
Why NoSQL?
jnunemaker
PRO
10
910
Don't Repeat Yourself, Repeat Others
jnunemaker
PRO
7
3.3k
I Have No Talent
jnunemaker
PRO
14
940
Other Decks in Programming
See All in Programming
もう僕は OpenAPI を書きたくない
sgash708
5
1.6k
Open source software: how to live long and go far
gaelvaroquaux
0
630
仕様変更に耐えるための"今の"DRY原則を考える / Rethinking the "Don't repeat yourself" for resilience to specification changes
mkmk884
0
160
Kubernetes History Inspector(KHI)を触ってみた
bells17
0
230
定理証明プラットフォーム lapisla.net
abap34
1
1.8k
2024年のkintone API振り返りと2025年 / kintone API look back in 2024
tasshi
0
220
Grafana Loki によるサーバログのコスト削減
mot_techtalk
1
130
社内フレームワークとその依存性解決 / in-house framework and its dependency management
vvakame
1
560
個人アプリを2年ぶりにアプデしたから褒めて / I just updated my personal app, praise me!
lovee
0
340
Honoのおもしろいミドルウェアをみてみよう
yusukebe
1
210
pylint custom ruleで始めるレビュー自動化
shogoujiie
0
120
CSS Linter による Baseline サポートの仕組み
ryo_manba
1
100
Featured
See All Featured
The MySQL Ecosystem @ GitHub 2015
samlambert
250
12k
Navigating Team Friction
lara
183
15k
Stop Working from a Prison Cell
hatefulcrawdad
267
20k
Building Flexible Design Systems
yeseniaperezcruz
328
38k
Adopting Sorbet at Scale
ufuk
74
9.2k
Fontdeck: Realign not Redesign
paulrobertlloyd
83
5.4k
A Modern Web Designer's Workflow
chriscoyier
693
190k
Docker and Python
trallard
44
3.3k
Understanding Cognitive Biases in Performance Measurement
bluesmoon
27
1.6k
BBQ
matthewcrist
87
9.5k
Principles of Awesome APIs and How to Build Them.
keavy
126
17k
The Success of Rails: Ensuring Growth for the Next 100 Years
eileencodes
44
7k
Transcript
loops executing code over and over again Thursday, September 24,
2009
Thursday, September 24, 2009
for loop loop a specified number of times; the only
loop you need to know http://www.w3schools.com/jS/js_loop_for.asp Thursday, September 24, 2009
for (var i=0; i < 5; i++) { // some
code to run } Thursday, September 24, 2009
for (var i=0; i < 5; i++) { // some
code to run } before any loops Thursday, September 24, 2009
for (var i=0; i < 5; i++) { // some
code to run } before each loop Thursday, September 24, 2009
for (var i=0; i < 5; i++) { // some
code to run } after each loop Thursday, September 24, 2009
for (var i=0; 0 < 5; i++) { // i
would be 0 } Thursday, September 24, 2009
for (var i=0; 1 < 5; i++) { // i
would be 1 } Thursday, September 24, 2009
for (var i=0; 2 < 5; i++) { // i
would be 2 } Thursday, September 24, 2009
for (var i=0; 3 < 5; i++) { // i
would be 3 } Thursday, September 24, 2009
for (var i=0; 4 < 5; i++) { // i
would be 4 } Thursday, September 24, 2009
for (var i=0; 5 < 5; i++) { // condition
false so this // would never happen } Thursday, September 24, 2009
for (var i=0; 5 < 5; i++) { // condition
false so this // would never happen } Thursday, September 24, 2009
var colors = ['red', 'green', 'blue']; for(var i=0; i <
colors.length; i++) { colors[i]; } Thursday, September 24, 2009
var colors = ['red', 'green', 'blue']; for(var i=0, length=colors.length; i
< length; i++) { colors[i]; } Thursday, September 24, 2009
var colors = ['red', 'green', 'blue']; var length = colors.length;
for(var i=0; i < length; i++) { colors[i]; } Thursday, September 24, 2009
while loop loop while a condition is true http://www.w3schools.com/JS/js_loop_while.asp Thursday,
September 24, 2009
var i = 0; while (i < 5) { //
some code to run i++; } Thursday, September 24, 2009
var i = 0; while (i < 5) { //
some code to run i++; } before each loop Thursday, September 24, 2009
var i = 0; while (0 < 5) { //
i would be 0 i++; // i would be 1 } Thursday, September 24, 2009
var i = 0; while (1 < 5) { //
i would be 1 i++; // i would be 2 } Thursday, September 24, 2009
var i = 0; while (2 < 5) { //
i would be 2 i++; // i would be 3 } Thursday, September 24, 2009
var i = 0; while (3 < 5) { //
i would be 3 i++; // i would be 4 } Thursday, September 24, 2009
var i = 0; while (4 < 5) { //
i would be 4 i++; // i would be 5 } Thursday, September 24, 2009
var i = 0; while (5 < 5) { //
condition is false so // this would never happen i++; } Thursday, September 24, 2009
var i = 0; while (5 < 5) { //
condition is false so // this would never happen i++; } Thursday, September 24, 2009
for..in loop loop through the properties of an object http://www.w3schools.com/jS/js_loop_for_in.asp
Thursday, September 24, 2009
for (property in object) { // some code here }
Thursday, September 24, 2009
var person = { name: 'John Nunemaker', age: 27, married:
true, cat_owner: 'unfortunately' }; for (property in person) { property; person[property]; } Thursday, September 24, 2009
var person = { name: 'John Nunemaker', age: 27, married:
true, cat_owner: 'unfortunately' }; for (property in person) { property; // ‘name’ person[property]; // ‘John Nunemaker’ } Thursday, September 24, 2009
var person = { name: 'John Nunemaker', age: 27, married:
true, cat_owner: 'unfortunately' }; for (property in person) { property; // ‘age’ person[property]; // 27 } Thursday, September 24, 2009
var person = { name: 'John Nunemaker', age: 27, married:
true, cat_owner: 'unfortunately' }; for (property in person) { property; // ‘married’ person[property]; // true } Thursday, September 24, 2009
var person = { name: 'John Nunemaker', age: 27, married:
true, cat_owner: 'unfortunately' }; for (property in person) { property; // ‘cat_owner’ person[property]; // ‘unfortunately’ } Thursday, September 24, 2009
break break the current loop and continue with code after
loop if any http://www.w3schools.com/jS/js_break.asp Thursday, September 24, 2009
think “stop looping right now” Thursday, September 24, 2009
for (var i=0; i < 5; i++) { if (i
=== 2) { break; } i; } Thursday, September 24, 2009
for (var i=0; 0 < 5; i++) { if (0
=== 2) { // false break; } i; // 0 } Thursday, September 24, 2009
for (var i=0; 0 < 5; i++) { if (0
=== 2) { // false break; } i; // 0 } Thursday, September 24, 2009
for (var i=0; 1 < 5; i++) { if (1
=== 2) { // false break; } i; // 1 } Thursday, September 24, 2009
for (var i=0; 1 < 5; i++) { if (1
=== 2) { // false break; } i; // 1 } Thursday, September 24, 2009
for (var i=0; 2 < 5; i++) { if (2
=== 2) { // true break; // breaks out of loop } i; // never gets here } Thursday, September 24, 2009
for (var i=0; 2 < 5; i++) { if (2
=== 2) { // true break; // breaks out of loop } i; // never gets here } Thursday, September 24, 2009
most common use is switch statement, but good to know
it works elsewhere Thursday, September 24, 2009
continue break the current loop and continue with the next
value http://www.w3schools.com/jS/js_break.asp Thursday, September 24, 2009
think “skip current loop” Thursday, September 24, 2009
for (var i=0; i < 3; i++) { if (i
=== 1) { continue; } i; // comment } Thursday, September 24, 2009
for (var i=0; 0 < 3; i++) { if (0
=== 1) { // false continue; } i; // 0 } Thursday, September 24, 2009
for (var i=0; 0 < 3; i++) { if (0
=== 1) { // false continue; } i; // 0 } Thursday, September 24, 2009
for (var i=0; 1 < 3; i++) { if (1
=== 1) { // true continue; } i; // never gets here } Thursday, September 24, 2009
for (var i=0; 1 < 3; i++) { if (1
=== 1) { // true continue; } i; // never gets here } Thursday, September 24, 2009
for (var i=0; 2 < 3; i++) { if (2
=== 1) { // false continue; } i; // 2 } Thursday, September 24, 2009
for (var i=0; 2 < 3; i++) { if (2
=== 1) { // false continue; } i; // 2 } Thursday, September 24, 2009
for (var i=0; 3 < 3; i++) { // never
gets here if (i === 1) { continue; } i; } Thursday, September 24, 2009
for (var i=0; 3 < 3; i++) { // never
gets here if (i === 1) { continue; } i; } Thursday, September 24, 2009
assignment04 http://teaching.johnnunemaker.com/capp-30550/sessions/looping/ Thursday, September 24, 2009