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    <p>Split does not create brand new strings, it uses <code>substring</code> internally which creates a new <code>String</code> object that points to the right substring of the original string, without copying the underlying <code>char[]</code>.</p> <p>So apart from the (slight) overhead of object creation, it should not have a huge impact from a memory perspective.</p> <p>ps: <code>StringTokenizer</code> uses the same technique so it would probably yield the same results as split.</p> <p><strong>EDIT</strong> </p> <p>To see that it is the case, you can use the sample code below. It splits <code>abc,def</code> into <code>abc</code> and <code>def</code> then prints the underlying <code>char[]</code> of the original string and of the split strings - the output shows that they are all the same.</p> <p>Output:</p> <pre class="lang-none prettyprint-override"><code>Reference: [C@3590ed52 Content: [a, b, c, ,, d, e, f] Reference: [C@3590ed52 Content: [a, b, c, ,, d, e, f] Reference: [C@3590ed52 Content: [a, b, c, ,, d, e, f] </code></pre> <p>Code:</p> <pre><code>public static void main(String[] args) throws InterruptedException, NoSuchFieldException, IllegalArgumentException, IllegalAccessException { String s = "abc,def"; String[] ss = s.split(","); Field f = String.class.getDeclaredField("value"); f.setAccessible(true); System.out.println("Reference: " + f.get(s) + "\tContent: " + Arrays.toString((char[])f.get(s))); System.out.println("Reference: " + f.get(ss[0]) + "\tContent: " + Arrays.toString((char[])f.get(ss[0]))); System.out.println("Reference: " + f.get(ss[1]) + "\tContent: " + Arrays.toString((char[])f.get(ss[1]))); } </code></pre>
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    1. POMemory issues with String.split()
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    1. USassylias
    1. USassylias
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    1. COin the substring method, it will finally create a new String with the new String(offset + beginIndex, endIndex - beginIndex, value), and when new String(xxx) was called, the jvm`ll make a copy of char[] value in the cache pool once it`s not existed , is that correct ?
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    2. COno the new string will use the same `char[]` as the original one. Now if you split to only keep a small portion of the original string, you will actually carry the whole string around as you keep a reference to its `char[]` in each of the substrings.
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    3. COSorry, i just read the source code, and i was wrong. it does use the copy to improve the memory performance
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