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Commit 5bfe3bd
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// You might think we can just do something like this:
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// team[3] = 'Lux';
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// You might think we can just do something like this:
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// however what happens when we update that array?
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// however what happens when we update that array?
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// now here is the problem!
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// now here is the problem!
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// oh no - we have edited the original array too!
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// oh no - we have edited the original array too!
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// Why? It's because that is an array reference, not an array copy. They both point to the same array!
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// Why? It's because that is an array reference, not an array copy. They both point to the same array!
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// So, how do we fix this? We take a copy instead!
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constteam2=players.slice();
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// So, how do we fix this? We take a copy instead!
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// one way
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// one way
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// or create a new array and concat the old one in
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constteam3=[].concat(players);
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// or create a new array and concat the old one in
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// or use the new ES6 Spread
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constteam4=[...players];
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team4[3]='heeee hawww';
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console.log(team4);
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// or use the new ES6 Spread
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constteam5=Array.from(players);
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// now when we update it, the original one isn't changed
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// now when we update it, the original one isn't changed
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// The same thing goes for objects, let's say we have a person object
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// The same thing goes for objects, let's say we have a person object
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// with Objects
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constperson={
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name: 'Wes Bos',
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age: 80
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};
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// with Objects
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constperson={
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name: 'Wes Bos',
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age: 80
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};
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// and think we make a copy:
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// and think we make a copy:
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// const captain = person;
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// captain.number = 99;
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// how do we take a copy instead?
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// how do we take a copy instead?
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constcap2=Object.assign({},person,{
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number: 99,
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age: 12
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});
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console.log(cap2);
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// We will hopefully soon see the object ...spread
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// We will hopefully soon see the object ...spread
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// const cap3 = {...person};
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// Things to note - this is only 1 level deep - both for Arrays and Objects. lodash has a cloneDeep method, but you should think twice before using it.
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// Things to note - this is only 1 level deep - both for Arrays and Objects. lodash has a cloneDeep method, but you should think twice before using it.
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