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R4.01_R4.A.10/td_tp/tp1/aide.md

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+#### Élement d'un document
+
+```js
+
+let x = document.getElementById(MOVE_VAL_ID)
+let images = document.querySelectorAll('img')
+```
+
+#### Changer le contenu texte d'un élément
+```js
+document.getElementById('message').textContent = "hello world !"
+```
+
+#### Nombre aléatoire
+
+```js
+let r=Math.random();
+if (r<0.5) 
+	console.log("Face");
+else
+	console.log("Pile");
+```
+#### Timers
+
+```js
+setTimeout(()=>console.log("3 secondes écoulées"),3000);
+
+let i = setInterval(
+	() => { 
+		let d = (new Date()).toLocaleTimeString();
+		document.getElementById("time").innerText = d;
+	},
+	1000)
+
+setTimeout(()=>clearInterval(i),10000);
+```
+
+#### Réponse à un événement
+```js
+// inline DOM 0
+img.onclick = function(){ console.log("clicked !")}
+
+// DOM >= 2
+img.addEventListener("click",()=>console.log("clicked"));
+
+```
+
+
+#### Itération d'un tableau
+
+```js
+let a = [1,2,3];
+
+// forEach
+a.forEach( elem => console.log(elem));
+
+// for ... of 
+// valable pour tous les itérables
+//  Array, Map, Set, String, etc.
+
+for (let elem of a){
+	console.log(elem);
+}
+```
+
+
+#### Tri d'un tableau
+
+```js
+const activities = [
+  { title: 'Hiking', date: new Date('2019-06-28') },
+  { title: 'Shopping', date: new Date('2019-06-10') },
+  { title: 'Trekking', date: new Date('2019-06-22') }
+]
+
+const sortedActivities = activities.sort((a, b) => b.date - a.date);
+
+```
+
+#### Itération d'un tableau avec  map, filter, reduce et find.
+
+```js
+// map
+const items = ['a', 'b', 'c']
+const newArray = items.map((item) => performSomething(item))
+const newArray = items.map(performSomething)
+
+// find
+const items = [
+  { name: 'a', content: { /* ... */ }},
+  { name: 'b', content: { /* ... */ }},
+  { name: 'c', content: { /* ... */ }}
+]
+const b = items.find((item) => item.name === 'b')
+
+//reduce
+const items = [
+  { name: 'a', content: { value: 1 }},
+  { name: 'b', content: { value: 2 }},
+  { name: 'c', content: { value: 3 }}
+]
+
+const count = items.reduce((result, elem ) => result + elem.content.value, 0)
+// en decomposant l'objet !
+const count = items.reduce((result, { content: { value } }) => result + value, 0)
+
+```
+
+#### Division d'une chaîne de caractères avec split
+```js
+const str = 'a,b,c,d,e'
+const l = str.split(',')
+
+// l = [ "a","b","c","d","e"]
+```