How to use continue in es6

In ES6, the continue statement is used to skip subsequent statements in the current iteration and bring control back to the beginning of the loop; continue does not exit the loop, but terminates the current iteration and starts subsequent iterations, syntax is "for(...){...continue}".

The operating environment of this tutorial: Windows 10 system, ECMAScript version 6.0, Dell G3 computer.

How to use continue in es6

The continue statement skips subsequent statements in the current iteration and brings control back to the beginning of the loop. Unlike the break statement, continue does not exit the loop. It terminates the current iteration and starts subsequent iterations. The following is an example of continue statement.

Example

var num = 0 
var count = 0; 
for(num = 0;num<= 20;num++) { 
   if (num % 2 == 0) { 
      continue 
   } 
   count++ 
} 
console.log(" The count of odd values between 0 and 20 is: "+count)

The above example shows even values ​​between 0 and 20. If the number is even, the loop exits the current iteration. This is achieved using the continue statement.

After successfully executing the above code, the following output will be displayed.

The count of odd values between 0 and 20 is: 10

Expand knowledge

es6 loop

1. for Loop

supports break and continue syntax, break terminates the loop, and continue skips this loop

2. forEach

does not support break and continue syntax, and the forEach loop does not accept control , must be traversed from beginning to end

3. every

    let arr = [1,2,3,4,5]
    arr.every((item) => {
        console.log(item)
        return true
    })

The syntax form of every is similar to forEach, it also accepts a function parameter, but the difference is that every requires a return value. When the return value is The next loop will be executed only when true, and false is returned by default. That is to say, the difference between every and forEach is that every accepts program control and can use the return value to achieve the effects of break and continue

4. for in

    let arr = [1,2,3,4,5]
    for(let index in arr) {
        console.log(arr[index])
    }

forin can also be used to loop through arrays, but there is a problem because forin is designed for traversing objects. The reason why arrays can be traversed is because the array is also an object, and the object can have attributes appended, such as in the above example. If attribute a is appended to arr, arr.a = 6, attribute a will also be traversed after forin is executed, but the index value a we understand in the array is not legal

forin also supports break and continue syntax

Note that the custom variable index in forin is an index, or attribute name, which is a string type. Pay attention to the variable type when making judgments

5. for of

    let arr = [1,2,3,4,5]
    for(let item of arr) {
        console.log(item)
    }

for of is a new syntax for ES6, mainly to solve the problem of custom data type traversal. It can also traverse arrays, but its function is more powerful than the other traversal methods mentioned above.

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