question: how to determine the number of digits entered by the user, and alert out
condition: assume that the user can only enter numbers. Type is number
for example: user typed 1234, click submit and alert out 4;
user entered 456454579988, click submit after alert comes out is 12;
above is my request to get out with JS, because I am a beginner, did not come into contact with regular expressions, please do not use regular, because do not understand!
this has to be tested. What you enter may be a combination of numbers, letters, underscores, special symbols, etc., but all you have to do is write a for loop, regular matching in the loop body, and you have to check out the numbers and count them.
I am a rookie, please spray
1. First of all, determine whether it is a number
2. If it's just a simple integer, the number you enter
var num = ;
alert(num.toString().length);3. If there is a decimal point (I don't know if this is correct)
var num =
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