Day23 JS notes 2021.09.14

while Loop structure

while( Conditional statements ){
     Conditional execution code
}    

do while Loop structure

do while Cycle is while Circulating variants . The cycle flow is similar , The only difference is do while The loop executes once first , Whether or not the conditions are valid , Do it first , The following process and while The cycle is the same .

for Loop structure

for( Declare variables and assign initial values ; Conditional expression ; The change law of the variable after each repetition ){
    Repeated code block
}
# Declare variables and assign initial values in the syntax , Is where to start repeating ; Conditional expressions can limit when repetition stops （ When conditions don't hold ）; You can know how many times to repeat by repeating the change of the variable and the conditional expression each time

Jump keyword in loop

continue keyword , You can skip the current cycle , Go straight to the next cycle .

break keyword , Can terminate the cycle , Let the whole cycle run directly .

Nesting of loops

for(var i=1;i<=5;i++){
    for(var j=1;j<=5;j++){
        document.write(" The first " + i + " Individual runner " + j + " circle <br>");
    }
}