如何使用 JavaScript 删除小数点后的数字？

Question

I am using numeric in an HTML web page. The problem is that I want numbers without decimals.

 function copyText() { var mynumber = document.getElementById("field1").value; alert(mynumber); var mytest = parseInt(mynumber); }

 Field1: <input type="number" id="field1" value="123.124" /><br /><br /> <button onclick="copyText()">Check Number</button> <p>A function is triggered when the button is clicked. The function copies the text in Field1 to Field2.</p>

Answer 1

Assuming you just want to truncate the decimal part (no rounding), here's a shorter (and less expensive) alternative to parseInt() or Math.floor() :

var number = 1.23;
var nodecimals = number | 0; // => 1

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Further examples for the bitwise OR 0 behavior with int , float and string input:

10     | 0 // => 10
10.001 | 0 // => 10
10.991 | 0 // => 10
"10"   | 0 // => 10
"10.1" | 0 // => 10
"10.9" | 0 // => 10

Answer 2

你应该使用 JavaScript 的parseInt()

Answer 3

In ES6 , you can use builtin method trunc from Math Object

 Math.trunc(345.99933)

Answer 4

var num = 233.256;
console.log(num.toFixed(0));

//output 233

Answer 5

returns string:

(.17*parseInt(prescription.values)*parseInt(cost.value)).toFixed(0);

returns integer:

Math.round(.17*parseInt(prescription.values)*parseInt(cost.value));

Remember to use radix when parsing ints:

parseInt(cost.value, 10)

Answer 6

Mathematically, using a floor function makes the most sense. This gives you a real number to the largest previous integer.

ans7 = Math.floor(.17*parseInt(prescription.values)*parseInt(cost.value));

Answer 7

Have you try to get value using parseInt

Try :

console.log(parseInt(ans7));

Answer 8

~~ operator is a faster substitute for Math.floor() .

 function copyText() { var mynumber = document.getElementById("field1").value; alert(~~mynumber); }

 <fieldset> <legend>Field1</legend> <input type="number" id="field1" value="123.124" /> <button onclick="copyText()">Check Number</button> </fieldset>