I assume you're referring to a 1776-1976 US quarter. The reverse side shows a drummer boy, not a sentinel.
If you found the coin in change, it's only worth 25¢. An uncirculated one might sell for a couple of dollars, while a 40%-silver proof or uncirculated one might retail for $4 or $5.
A 1967 Washington quarter has no silver and is face value.
The coin is a 2001 Vermont State Quarter, it's 25 cents.
The 1861 Liberty Seated quarter has a average starting value of $25.00. But if it's a 2005 Kansas State quarter, just spend it.
No 1957 quarter is rare and I have no info on grade but the scrap value is about $3.00 each.
It's just a quarter spend it
A sentinel loop is a loop that iterates over a series of values until a special "sentinel" value is encountered. For instance, when iterating over the characters in a string, the null-terminator acts as the sentinel value, indicating that the end of the string has been reached. Sentinel loops typically have the following form: while( get_value(value) != sentinel ) { // do something with value... }
A sentinel-controlled repetition is a loop structure where the continuation of the loop is determined by a special condition called a sentinel value. When the sentinel value is encountered, it signals the end of the loop. This allows the loop to run until a specific condition is met, rather than for a predetermined number of iterations.
In a Sentinel-Controlled loop, a special value called a sentinel value is used to change the loop control expression from true to false.For example,when reading data we may indicate the "end of data" by a special value,like -1 and 999.The control variable is called sentinel variable.A sentinel-Controlled loop is often called indefinite repetition loop because the number of repetitions is not known before the loop begins executing.
Sentinel
hilhlik
50-100 USD
Depending on condition, $200-$250
A sentinel value in looping refers to a value whose presence terminates a given loop.
Sentinel
The value must be unique enough that it will not be mistaken as a regular value in the list.
15-150 USD or so
50-300 usd