In a chat the concept of private variables in a javascript object came up. I had seen it before but never really had done them before so I thought I would play around with it a bit.
Javascript by default does not have private variables. If you have variables that need to be ‘read-only’ or ‘private’ you can limit it’s visibility with a closure inside your constructor function.
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var foo = function(a) {
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var privateVar = a;
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this.getPrivate = function() {
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return a;
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}
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this.setPrivate = function(newvar) {
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a = newvar;
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}
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}
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var bar = new foo(1000);
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alert(bar.getPrivate()); // Alerts 1000
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bar.setPrivate(‘Hello’); // Sets privateVar to ‘Hello’
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alert(bar.getPrivate()); // Alerts ‘Hello’
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alert(bar.privateVar); // Alerts ‘undefined’
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