javascript循环似乎不起作用

Question

I expected the code snippet to print out 100 times with the value of i.

But it prints out only once like below.

What am I missing here ?

 let i = 0; for (; i++; i < 100) { console.log('Loop ==>' + i); } console.log('Loop Done'); console.log('Value of i ==>' + i); 

Answer 1

You have to write loop like below -

 <script>
    let i=0;
                        for(;i<100;i++)
                        {
                              console.log('Loop ==>'+i);
                        }
                        console.log('Loop Done');
                        console.log('Value of i ==>'+i);        
    </script> 

Answer 2

You mixed the "condition" and "change" places in your for loop. Condition is in the second place and change in the third place.

 let i = 0; for(; i < 100; i++) { console.log('Loop ==>'+i); } console.log('Loop Done'); console.log('Value of i ==>'+i); 

Answer 3

Your for loop's structure is faulty. You should use the correct syntax, like this.

for (; i < 100; i++)

for loops have 3 statements, initialization, condition and updation, in that order. The loop runs as long as the second statement, ie, the condition is met. The third statement, ie, updation, is executed after all the code in your block is executed.

What you have done is you have mixed up the third (updation) and the second (condition) statements in your for loop.

Answer 4

Change ; i++; i < 100 ; i++; i < 100 ; i++; i < 100 to ; i < 100; i++ ; i < 100; i++ ; i < 100; i++ . In the former case i value is incremeneted and tested if less than 100, whereas it need the opposite

 let i = 0; for (; i < 100; i++) { console.log('Loop ==>' + i); } console.log('Loop Done'); console.log('Value of i ==>' + i);