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    <p><strong>Writing a "delete named product from hash" method</strong></p> <p>There are shorter ways of doing it, but shooting for clarity I came up with this:</p> <pre><code>products = {124 =&gt; ['shoes', 59.99], 352 =&gt; ['shirt', 19.99], 777 =&gt; ['pants', 19.87], 667 =&gt; ['jacket', 39.99], 898 =&gt; ['shoulder_holster', 22.78]} def wipeProduct(hash, nameToDelete) hash.each do |i| key = i[0] productName = i[1].first hash.delete(key) if productName==nameToDelete end end puts products.inspect wipeProduct(products,'pants') puts products.inspect wipeProduct(products,'shoulder_holster') puts products.inspect bash-3.2$ ruby prod.rb {352=&gt;["shirt", 19.99], 898=&gt;["shoulder_holster", 22.78], 667=&gt;["jacket", 39.99], 777=&gt;["pants", 19.87], 124=&gt;["shoes", 59.99]} {352=&gt;["shirt", 19.99], 898=&gt;["shoulder_holster", 22.78], 667=&gt;["jacket", 39.99], 124=&gt;["shoes", 59.99]} {352=&gt;["shirt", 19.99], 667=&gt;["jacket", 39.99], 124=&gt;["shoes", 59.99]} </code></pre> <p>I don't know if it's possible for "pants" to occur in the hash in multiple places, but since I used "hash.each(...)", the method wipeProduct(hash, nameToDelete) will test every hash entry.</p> <p><strong>The input type bug and how to fix it</strong></p> <p>When you take input, you're assigning the string you captured to d. Here's the proof:</p> <pre><code>irb(main):010:0&gt; d = gets.to_s 12 =&gt; "12\n" irb(main):011:0&gt; d.class =&gt; String </code></pre> <p>You can convert that string to a Fixnum like this:</p> <pre><code>irb(main):012:0&gt; d.to_i =&gt; 12 irb(main):013:0&gt; d.to_i.class =&gt; Fixnum </code></pre> <p>All keys in the products hash are Fixnums. Here's the proof:</p> <pre><code>irb(main):014:0&gt; products.keys.each {|i| puts i.class} Fixnum Fixnum Fixnum Fixnum Fixnum =&gt; [352, 898, 667, 777, 124] </code></pre> <p>So you need to capture the value for the argument with this line:</p> <pre><code>d = gets.to_i # Get value for argument </code></pre> <p><strong>The deletion part of the answer:</strong></p> <p>From products, you can delete the pants entry programmatically with this:</p> <p>products.delete(777)</p> <p>Running it gets you this:</p> <pre><code>irb(main):003:0&gt; products.delete(777) =&gt; ["pants", 19.87] </code></pre> <p>Notice that you supply the key value (in this case 777) to .delete() and that it returns an array consisting of the key and value in that order respectively.</p> <p><strong>An alternative implementation</strong></p> <p>I'm not sure if it's safe to modify a hash in a block that's iterating over the key-value pairs in the hash. If it isn't, you can just save up all the keys to be deleted and delete them after iterating over the hash:</p> <pre><code>def wipeProduct(hash, nameToDelete) keysToDelete = [] hash.each do |i| key = i[0] productName = i[1].first keysToDelete &lt;&lt; key if productName==nameToDelete end keysToDelete.each {|key| hash.delete(key) } end </code></pre>
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