There are times when we need to execute a code segment repeatedly based on a condition. Solidity provides while loops precisely for this purpose. The general form of the while loop is as follows:
Declare and initialize a counterwhile (check the value of counter using an expression or condition) { Execute the instructions here Increment the value of counter}
while is a keyword in Solidity and it informs the compiler that it contains a decision control instruction. If this expression evaluates to true then the code instructions that follow in the pair of double-brackets { and } should be executed. The while loop keeps executing until the condition turns false.
In the following example, mapping is declared along with counter ...