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<!--replace-end-7--><!--replace-end-4--><!--replace-end-1--></head><body><div class="ui fluid container universe"><!--replace-start-2--><!--replace-start-3--><!--replace-start-6--><div class="ui text container" id="zettel-container" style="position: relative"><div class="zettel-view"><article class="ui raised attached segment zettel-content"><div class="pandoc"><h1 id="title-h1">Function overloads</h1><p>Function overloading is not a feature of JavaScript but something close to it can be achieved with TypeScript. It proceeds by defining multiple function types (defined above the function) that may serve as the actual function’s parameters. Then with the actual function, you leave the changeable parameters open as optional unions and/or <code>unknown</code> :</p><pre><code class="ts language-ts">// First oveload type:
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function logSearch(term: string, options?: string): void;
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// Second overload type:
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function logSearch(term: string, options?: number): void;
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// Implementation:
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function logSearch(term: string, p2?: unknown) {
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let query = `https://searchdatabase/${term}`;
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if (typeof p2 === "string") {
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query = `${query}/tag=${p2}`;
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console.log(query);
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} else {
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query = `${query}/page=${p2}`;
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console.log(query);
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}
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}
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logSearch("apples", "braeburn");
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logSearch("bananas", 3);</code></pre><pre><code class="ts language-ts">// First overload type:
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function logSearchUnion(term: string, options?: string): void;
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// Second overload type:
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function logSearchUnion(term: string, options?: number): void;
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// Implementation:
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function logSearchUnion(term: string, p2?: string | number) {
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let query = `https://searchdatabase/${term}`;
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if (typeof p2 === "string") {
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query = `${query}/tag=${p2}`;
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console.log(query);
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} else {
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query = `${query}/page=${p2}`;
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console.log(query);
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}
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}
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logSearchUnion("melon", "honey-dew");
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logSearchUnion("oranges", 4);</code></pre></div></article><nav class="ui attached segment deemphasized bottomPane" id="neuron-tags-pane"><div><span class="ui basic label zettel-tag" title="Tag">typescript</span></div></nav><nav class="ui bottom attached icon compact inverted menu blue" id="neuron-nav-bar"><!--replace-start-9--><!--replace-end-9--><a class="right item" href="impulse.html" title="Open Impulse"><i class="wave square icon"></i></a></nav></div></div><!--replace-end-6--><!--replace-end-3--><!--replace-end-2--><div class="ui center aligned container footer-version"><div class="ui tiny image"><a href="https://neuron.zettel.page"><img alt="logo" src="https://raw.githubusercontent.com/srid/neuron/master/assets/neuron.svg" title="Generated by Neuron 1.9.35.3" /></a></div></div></div></body></html> |