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JavaScript

brandonlind2
brandonlind2
7,823 Points
Posted by brandonlind2
brandonlind2
7,823 Points

Can someone explain this different javascript syntax?

const neuron = ({ synapses = [], threshold = 1 } = {} /*im confused by these, it passes 
an object literal equal to an empty object? what?*/) => ({
  synapses,
  threshold
}/*im confused these (), after the arrow*/ );

//code without comments
const neuron = ({ synapses = [], threshold = 1 } = {}) => ({
  synapses,
  threshold
});

[mod edit - formatting]

1 Answer

Seth Kroger
Seth Kroger
56,413 Points
Seth Kroger
Seth Kroger
56,413 Points

It's a combination of defaut paramenters and destructuring assignment, specifically this. The function will take an object as an argument but if synapses or threshold are missing it will supply the given defaults.

neuron();
  // returns { synapses: [], threshold: 1 }
neuron({synapses: [1,2]});
  // returns { synapses: [1,2], threshold: 1 }