sizeofStr

Signatures

• uint16_t SPIFlash::sizeofStr(String &inputStr)
• uint16_t SPIFram::sizeofStr(String &inputStr)

What It Is For

Compute storage footprint required by library string routines so allocations and erase sizes match serialized length.

Parameters

• inputStr: String value to size for storage/readback routines.

Behavior Details

Use with getAddress() and erase calls before writing strings to prevent under-allocation.

Return Semantics

Returns required byte count for storing that specific String.

Failure Behavior

If you erase/write fewer bytes than required, reads can truncate or include stale residual bytes.

Common Mistakes

• Using String.length() instead of sizeofStr() for storage planning.
• Erasing fewer bytes than string storage actually requires.
• Reusing old allocation size after string content grows.

Choosing Between Similar APIs

• Use sizeofStr() before writeStr() for exact storage planning.
• Use writeCharArray() when you need explicit fixed-length text layout.
• Prefer fixed-length arrays over String in hard real-time memory maps.

Example

String name = "sensor-A";
uint16_t sz = flash.sizeofStr(name);
uint32_t addr = flash.getAddress(sz);
flash.eraseSection(addr, sz);
flash.writeStr(addr, name);