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This article is about how JS can generate CAPTCHA randomly. The editor thinks it is very practical, so share it with you as a reference and follow the editor to have a look.

The details are as follows

111111 can't see another CAPTCHA: make sure var arr = ["A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z" "a", "b", "c", "d", "e", "f", "g", "h", "I", "j", "k", "l", "m", "n", "o", "p", "Q", "r", "s", "t", "u", "v", "w", "x", "y", "z", 0r 1, 3, 4, 6, 7, 8] Var h2=document.querySelector ("H2"); var btn=document.querySelector ("button"); var change=document.querySelector ("a"); var input=document.querySelector ("input"); function fn () {var arr1=Math.floor (Math.random () * 62); var arr2=Math.floor (Math.random () * 62); var arr3=Math.floor (Math.random () * 62) Var arr4=Math.floor (Math.random () * 62); var arr5=Math.floor (Math.random () * 62); var arr6=Math.floor (Math.random () * 62); var yz= "+ arr [arr1] + arr [arr2] + arr [arr3] + arr [arr4] + arr [arr5] + arr [arr6]; H2 [XSS _ clean] = yz; btn.onclick=function () {alert (input.value) If (input.value==yz) {alert (correct);} else {alert (error);} fn (); change.addEventListener ("click", fn)

1. Math.floor () method

Math.floor (x)

The floor () method returns the largest integer less than or equal to x.

If the parameter passed is an integer, the value remains the same.

2. Math.random () method

The random () method returns a random number between 0 (inclusive) and 1 (not inclusive).

The function of taking random numbers can be realized by using the above two methods.

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