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// b[] is a byte array, initialized to 0xff
byte[] b = new byte[] {-1, -1, -1, -1};
int result = 0;
for (int i = 0; i < 4; i++) {
  result = ((result << 8) + b[i]);
}

Wiki MarkupIn the bitwise operation, the value of the byte array element {{b\[i\]}} is promoted to an {{int}} by sign-extension. When a byte array element contains a negative value (for example, {{0xff}}), the sign-extension propagates 1-bits into the upper 24 bits of the {{int}}. This behavior might be unexpected if the programmer is assuming that {{byte}} is an unsigned type. In this example, adding the promoted byte values to {{result}} fails to result in a packed integer representation of the bytes \ [[FindBugs 2008|AA. References#FindBugs 08]\].

Noncompliant Code Example

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Bibliography

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      03. Numeric Types and Operations (NUM)      NUM02-J. Ensure that division and modulo operations do not result in divide-by-zero errors