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July 21, 2017 19:40
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Different Ways of iterating through lists.
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| // Adding a property to the global Object => all objects inherit from this. ex: toString method and prototype. | |
| Object.prototype.WTF = "this should not be in your object"; | |
| function a() { | |
| this.unwanted = 10; | |
| this.crap = "dhjbjbfdjbf"; | |
| } | |
| function child() { | |
| this.a = 1; | |
| this.b = 2; | |
| } | |
| //child inherits from a | |
| child.prototype = new a(); | |
| var obj = new child(); | |
| for (var property in obj) { // Not only is this slower than Object.keys, but it also contains the parent properties | |
| console.log(property + ": " + obj[property]); | |
| } | |
| for (var property in obj) { // This will return the proper keys but it is still 50% slower than Object.keys | |
| if(obj.hasOwnProperty(property)) | |
| console.log(property + ": " + obj[property]); | |
| } | |
| Object.keys(obj).map((e) => console.log(`key=${e} value=${obj[e]}`)); // best way ! | |
| Object.entries(obj).forEach(([key, value]) => console.log(`key=${key} value=${value}`)); // this one is good too! |
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