Claude
c5c435ae20
Co-Authored-By: Claude Sonnet 5.5 <[email protected]> Claude-Session: https://claude.ai/code/session_017ic4b5DfjBGLBr7F5km2AN
32 lines
1.0 KiB
Plaintext
32 lines
1.0 KiB
Plaintext
=== Q21 == vs equals() on Strings ===
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a == b -> true
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a == c -> false
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a.equals(c) -> true
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=== Q22 Why is String immutable? ===
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s = java
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upper = JAVA
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same object returned when nothing changes: true
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=== Q23 String vs StringBuilder vs StringBuffer ===
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builder result: cba-
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append is synchronized: StringBuffer=true, StringBuilder=false
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=== Q24 The string pool, compile-time constants and intern() ===
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"hel" + "lo" == "hello" -> true
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"hel" + lo == "hello" -> false
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"hel" + finalLo == "hello" -> true
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("hel" + lo).intern() == "hello" -> true
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=== Q25 Reverse a string and check for a palindrome ===
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weivretni
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true
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false
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=== Q26 Useful String methods and the split() surprises ===
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trim().length() = 6
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strip().length() = 2
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" ".isBlank() = true, "ab".repeat(3) = ababab
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"a,b,,".split(",").length = 2
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"a,b,,".split(",", -1).length = 4
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String.join: 2026-11-11
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=== Q27 Count characters, find the first non-repeating one, check anagrams ===
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frequency: {s=3, w=1, i=1}
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first non-repeating: w
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listen/silent anagrams: true
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