[jammaloo]

Add the -n flag to echo

echo -n "To begin with, for example, and to make sure your SHA-256 hash function is working, the hash value or checksum of this sentence, from capital 'T' to concluding colon, expressed in hexadecimal, is:" | sha256sum

Echo is automatically adding a newline

[umvi]

Editors like vi also add automatically add newlines to the end. You can check with hexdump if you have a newline or not:

    $ echo "To begin with, for example, and to make sure your SHA-256 hash function is working, the hash value or checksum of this sentence, from capital 'T' to concluding colon, expressed in hexadecimal, is:" | hexdump -C
    00000000  54 6f 20 62 65 67 69 6e  20 77 69 74 68 2c 20 66  |To begin with, f|
    00000010  6f 72 20 65 78 61 6d 70  6c 65 2c 20 61 6e 64 20  |or example, and |
    00000020  74 6f 20 6d 61 6b 65 20  73 75 72 65 20 79 6f 75  |to make sure you|
    00000030  72 20 53 48 41 2d 32 35  36 20 68 61 73 68 20 66  |r SHA-256 hash f|
    00000040  75 6e 63 74 69 6f 6e 20  69 73 20 77 6f 72 6b 69  |unction is worki|
    00000050  6e 67 2c 20 74 68 65 20  68 61 73 68 20 76 61 6c  |ng, the hash val|
    00000060  75 65 20 6f 72 20 63 68  65 63 6b 73 75 6d 20 6f  |ue or checksum o|
    00000070  66 20 74 68 69 73 20 73  65 6e 74 65 6e 63 65 2c  |f this sentence,|
    00000080  20 66 72 6f 6d 20 63 61  70 69 74 61 6c 20 27 54  | from capital 'T|
    00000090  27 20 74 6f 20 63 6f 6e  63 6c 75 64 69 6e 67 20  |' to concluding |
    000000a0  63 6f 6c 6f 6e 2c 20 65  78 70 72 65 73 73 65 64  |colon, expressed|
    000000b0  20 69 6e 20 68 65 78 61  64 65 63 69 6d 61 6c 2c  | in hexadecimal,|
    000000c0  20 69 73 3a 0a                                    | is:.|
    000000c5

If the string or file ends in `0a` you have a newline