From fe525731183779ef5b76cc714c47bd9033953e46 Mon Sep 17 00:00:00 2001 From: Raphael Nascimento Date: Tue, 6 Oct 2015 20:51:47 -0300 Subject: Update javascript.html.markdown For/In loop JavaScript --- javascript.html.markdown | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'javascript.html.markdown') diff --git a/javascript.html.markdown b/javascript.html.markdown index ba2e8ce4..3308b08d 100644 --- a/javascript.html.markdown +++ b/javascript.html.markdown @@ -218,6 +218,13 @@ for (var i = 0; i < 5; i++){ // will run 5 times } +//The For/In statement loops through the properties of an object: +var description = ""; +var person = {fname:"Paul", lname:"Ken", age:18}; +for (var x in person) { + description += person[x] + " "; +} + // && is logical and, || is logical or if (house.size == "big" && house.colour == "blue"){ house.contains = "bear"; -- cgit v1.2.3 From f1711ddd4c98633f059558b8d13e2532afbb5ba7 Mon Sep 17 00:00:00 2001 From: Raphael Nascimento Date: Tue, 6 Oct 2015 23:44:30 -0300 Subject: [javascript/en] Added for/in loop JavaScript more explanation about for/in java script. --- javascript.html.markdown | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) (limited to 'javascript.html.markdown') diff --git a/javascript.html.markdown b/javascript.html.markdown index 3308b08d..f7a662a4 100644 --- a/javascript.html.markdown +++ b/javascript.html.markdown @@ -218,13 +218,26 @@ for (var i = 0; i < 5; i++){ // will run 5 times } -//The For/In statement loops through the properties of an object: +//The For/In statement loops iterates over every property across the entire prototype chain var description = ""; var person = {fname:"Paul", lname:"Ken", age:18}; for (var x in person) { description += person[x] + " "; } +//If only want to consider properties attached to the object itself, +//and not its prototypes use hasOwnProperty() check +var description = ""; +var person = {fname:"Paul", lname:"Ken", age:18}; +for (var x in person) { + if( person.hasOwnProperty( x ) ) { + description += person[x] + " "; + } +} + +//for/in should not be used to iterate over an Array where the index order is important. +//There is no guarantee that for/in will return the indexes in any particular order + // && is logical and, || is logical or if (house.size == "big" && house.colour == "blue"){ house.contains = "bear"; -- cgit v1.2.3 From c3914e277bafb320a37617c4a41984462be1a20d Mon Sep 17 00:00:00 2001 From: Raphael Nascimento Date: Thu, 8 Oct 2015 18:34:03 -0300 Subject: Added for/in loop JavaScript Fixing code style --- javascript.html.markdown | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'javascript.html.markdown') diff --git a/javascript.html.markdown b/javascript.html.markdown index f7a662a4..0e38be8f 100644 --- a/javascript.html.markdown +++ b/javascript.html.markdown @@ -221,7 +221,7 @@ for (var i = 0; i < 5; i++){ //The For/In statement loops iterates over every property across the entire prototype chain var description = ""; var person = {fname:"Paul", lname:"Ken", age:18}; -for (var x in person) { +for (var x in person){ description += person[x] + " "; } @@ -229,8 +229,8 @@ for (var x in person) { //and not its prototypes use hasOwnProperty() check var description = ""; var person = {fname:"Paul", lname:"Ken", age:18}; -for (var x in person) { - if( person.hasOwnProperty( x ) ) { +for (var x in person){ + if (person.hasOwnProperty(x)){ description += person[x] + " "; } } -- cgit v1.2.3