while loop is a basic loop provided by language that executes a set of code statements until conditional_expression is met.


while conditional_expression do
    // body code statements

conditional_expression is a valid expression, that evaluates to a boolean value. if it is true, It executes the body. body code is always evaluated to the unit and does not return any value.

mutable Variable is declared with 0. Checking number is less than 5 and inside a body print number, increment the number by assigning using <- Here is an example

let mutable number = 0
while (number < 5) do
   printfn "%d" number
   number <- number + 1

Here is an example of an infinite loop with a while loop

Condition is true, code inside is always executed.

while true do
   printfn "infinite loop" 

How to break from while do the loop in F#?

F# has no break feature to exit from the while loop.

Alternatively, You can do using making a mutable conditional expression to false inside a body.

This is an ugly way of exit from a body inside while loop

let mutable isExit = false
let breakExpression=true;
while not isExit do
printfn "Inside Body" ;
    if breakExpression then
        isExit <- true

If you want a clean approach, write a recursion function that gets an exit at end interaction.