◼️The for statement creates a loop that consists of three optional expressions, enclosed in parentheses and separated by semicolons, followed by a statement (usually a block statement) to be executed in the loop.
Example:
const days = ['mon','tue','wed','thr','fri','sat'] //creating array
for (let index = 0; index <= days.length; index++) {
const element = days[index];
console.log(element)
// //OR
// console.log(days[index])
}
// //backward loop
for (let i = 5; i >= 0; i--) {
console.log(days[i])
}
for (let x = 1; x<=10 ; x++) {
console.log(2*x);
}
◼️For-each is another array traversing technique like for loop, while loop, do-while loop in Java Script.
Example1: For Each with simple function:
const days = ['mon','tue','wed','thr','fri','sat','sun']
// console.log(days[0])
let simple =function () { //simple is the onject of funtion
console.log('hello preet')
}
//this function prints 7 times hello preet as days store 7 values
days.forEach(simple)
Example2:
const days = ['mon','tue','wed','thr','fri','sat','sun']
days.forEach(function (day,index){
//day is its self element of string type in the array,
//2nd is the index value
console.log(`Start with ${index +1} ---${day}`)
})
◼️The
while and do...while statements in JavaScript are similar to Conditional Statement, which are blocks of code that will execute if a specified condition results in true. Unlike an if statement, which only evaluates once, a loop will run multiple times until the condition no longer evaluates to true.Example:
//while
var value=5;
while (value>0) {
console.log(value);
value--;
}
//Do-while
do {
console.log(value);
value--;
} while (value>6);
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