📂 JAVASCRIPT/Number & Math
[ 자바스크립트 ] 랜덤으로 실수를 가져오기 🕔 2016. 10. 26. 02:51
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[ Javascript ] Get real number at random.
random() 함수를 이용해서,
원하는 범위 안에서, 실수(real number) 하나를 랜덤으로 가져다주는 함수를 만들어보았다.
Using "Math.random()",
I wrote a function that returns one real number at random within the desired range.
<script type="text/javascript">
function getRandomNumber (){
var decimal;
var random = Math.random();
var isFirstNumber = function ( number ){ return ( "" + random ).indexOf( number ) == 0; };
switch ( arguments.length ){
case 0 :
if ( isFirstNumber( 0.001 ) ){ decimal = 0; }
else {
var decimalDigits = ( "" + random ).replace( "0.", "" ).length;
var exponential = Math.floor( Math.random() * decimalDigits );
decimal = ( exponential < 1 ) ? random : random * Math.pow( 10, exponential );
}
break;
case 1 :
if ( isFirstNumber( 0.001 ) ){ decimal = 0; }
else {
var max = Number( arguments[ 0 ] ) || parseFloat( arguments[ 0 ] );
if ( isNaN( max ) || max === 0 || isFirstNumber( 0.999 ) ){ decimal = max; }
else { decimal = random * max; }
}
break;
case 2 :
var temp, min, max;
temp = ( arguments[0] < arguments[1] ) ? arguments[0] : arguments[1];
min = Number( temp ) || parseFloat( temp );
temp = ( arguments[0] < arguments[1] ) ? arguments[1] : arguments[0];
max = Number( temp ) || parseFloat( temp );
if ( isNaN( min ) || isNaN( max ) || min == max ){ decimal = ( min == max ) ? max : NaN; }
else {
if ( isFirstNumber( 0.001 ) ){ decimal = min; }
else if ( isFirstNumber( 0.999 ) ){ decimal = max; }
else { decimal = ( random * (max - min) ) + min; }
}
break;
}
if ( isNaN( decimal ) ){ return { real : NaN, integer : NaN, positive : NaN, negative : NaN }; }
if ( decimal == 0 ){ return { real : 0, integer : 0, positive : 0, negative : 0 }; }
return { real : decimal,
integer : decimal - ( decimal % 1 ),
positive : ( decimal < 0 ) ? -decimal : decimal,
negative : ( decimal > 0 ) ? -decimal : decimal
};
}
</script>
아래는, 한정된 범위 없이 getRandomNumber() 함수를 실행했을 경우이다.
The following is a case of working the getRandomNumber() function without limited range.
<table>
<tbody>
<tr> <td>실수 ( real number ) </td> <td id="demo1"> </td> </tr>
<tr> <td>정수 ( integer ) </td> <td id="demo2"> </td> </tr>
<tr> <td>양수 ( positive number ) </td> <td id="demo3"> </td> </tr>
<tr> <td>음수 ( negative number ) </td> <td id="demo4"> </td> </tr>
</tbody>
</table>
<button onclick="testing()"> Click me </button>
<script type="text/javascript">
function testing (){
var random = getRandomNumber();
var a = random.real;
var b = random.integer;
var c = random.positive;
var d = random.negative;
demo1.innerHTML = a;
demo2.innerHTML = b;
demo3.innerHTML = c;
demo4.innerHTML = d;
}
</script>
| 실수 ( real number ) | |
| 정수 ( integer ) | |
| 양수 ( positive number ) | |
| 음수 ( negative number ) |
아래의 두 예문에서는, 0부터 14.09 사이의 실수(real number)를 가져온다.
최소값인 0과 최대값인 14.09도 나오기는 한다. 아주 가~~~끔...
The following two examples will return one real number between 0 and 14.09.
Very, very rarely...
it will return the minimum 0 or maximum 14.09.
<table>
<tbody>
<tr> <td>real number </td> <td id="demo1"> </td> </tr>
<tr> <td>integer </td> <td id="demo2"> </td> </tr>
<tr> <td>positive number </td> <td id="demo3"> </td> </tr>
<tr> <td>negative number </td> <td id="demo4"> </td> </tr>
</tbody>
</table>
<button onclick="testing()"> Click me </button>
<script type="text/javascript">
function testing (){
var random = getRandomNumber( 14.09 );
var a = random.real;
var b = random.integer;
var c = random.positive;
var d = random.negative;
demo1.innerHTML = a;
demo2.innerHTML = b;
demo3.innerHTML = c;
demo4.innerHTML = d;
}
</script>
| real number | |
| integer | |
| positive number | |
| negative number |
<table>
<tbody>
<tr> <td>real number </td> <td id="demo1"> </td> </tr>
<tr> <td>integer </td> <td id="demo2"> </td> </tr>
<tr> <td>positive number </td> <td id="demo3"> </td> </tr>
<tr> <td>negative number </td> <td id="demo4"> </td> </tr>
</tbody>
</table>
<button onclick="testing()"> Click me </button>
<script type="text/javascript">
function testing (){
var random = getRandomNumber( " 14.09 " );
var a = random.real;
var b = random.integer;
var c = random.positive;
var d = random.negative;
demo1.innerHTML = a;
demo2.innerHTML = b;
demo3.innerHTML = c;
demo4.innerHTML = d;
}
</script>
| real number | |
| integer | |
| positive number | |
| negative number |
아래 예문에서는, -14.09부터 0 사이의 실수(real number)를 가져온다.
The following returns one real number between -14.09 and 0.
<table>
<tbody>
<tr> <td>real number </td> <td id="demo1"> </td> </tr>
<tr> <td>integer </td> <td id="demo2"> </td> </tr>
<tr> <td>positive number </td> <td id="demo3"> </td> </tr>
<tr> <td>negative number </td> <td id="demo4"> </td> </tr>
</tbody>
</table>
<button onclick="testing()"> Click me </button>
<script type="text/javascript">
function testing (){
var random = getRandomNumber( -14.09 );
var a = random.real;
var b = random.integer;
var c = random.positive;
var d = random.negative;
demo1.innerHTML = a;
demo2.innerHTML = b;
demo3.innerHTML = c;
demo4.innerHTML = d;
}
</script>
| real number | |
| integer | |
| positive number | |
| negative number |
아래의 두 예문에서는, -3부터 5 사이의 실수(real number)를 가져온다.
The following two examples will return one real number between -3 and 5.
<table>
<tbody>
<tr> <td>real number </td> <td id="demo1"> </td> </tr>
<tr> <td>integer </td> <td id="demo2"> </td> </tr>
<tr> <td>positive number </td> <td id="demo3"> </td> </tr>
<tr> <td>negative number </td> <td id="demo4"> </td> </tr>
</tbody>
</table>
<button onclick="testing()"> Click me </button>
<script type="text/javascript">
function testing (){
var random = getRandomNumber( -3, 5 );
var a = random.real;
var b = random.integer;
var c = random.positive;
var d = random.negative;
demo1.innerHTML = a;
demo2.innerHTML = b;
demo3.innerHTML = c;
demo4.innerHTML = d;
}
</script>
| real number | |
| integer | |
| positive number | |
| negative number |
<table>
<tbody>
<tr> <td>real number </td> <td id="demo1"> </td> </tr>
<tr> <td>integer </td> <td id="demo2"> </td> </tr>
<tr> <td>positive number </td> <td id="demo3"> </td> </tr>
<tr> <td>negative number </td> <td id="demo4"> </td> </tr>
</tbody>
</table>
<button onclick="testing()"> Click me </button>
<script type="text/javascript">
function testing (){
var random = getRandomNumber( 5, -3 );
var a = random.real;
var b = random.integer;
var c = random.positive;
var d = random.negative;
demo1.innerHTML = a;
demo2.innerHTML = b;
demo3.innerHTML = c;
demo4.innerHTML = d;
}
</script>
| real number | |
| integer | |
| positive number | |
| negative number |
아래의 두 예문에서는, 결과가 모두 NaN으로 나올 것이다.
The following two examples will return NaN.
<table>
<tbody>
<tr> <td>real number </td> <td id="demo1"> </td> </tr>
<tr> <td>integer </td> <td id="demo2"> </td> </tr>
<tr> <td>positive number </td> <td id="demo3"> </td> </tr>
<tr> <td>negative number </td> <td id="demo4"> </td> </tr>
</tbody>
</table>
<button onclick="testing()"> Click me </button>
<script type="text/javascript">
function testing (){
var random = getRandomNumber( undefined );
var a = random.real;
var b = random.integer;
var c = random.positive;
var d = random.negative;
demo1.innerHTML = a;
demo2.innerHTML = b;
demo3.innerHTML = c;
demo4.innerHTML = d;
}
</script>
| real number | |
| integer | |
| positive number | |
| negative number |
<table>
<tbody>
<tr> <td>real number </td> <td id="demo1"> </td> </tr>
<tr> <td>integer </td> <td id="demo2"> </td> </tr>
<tr> <td>positive number </td> <td id="demo3"> </td> </tr>
<tr> <td>negative number </td> <td id="demo4"> </td> </tr>
</tbody>
</table>
<button onclick="testing()"> Click me </button>
<script type="text/javascript">
function testing (){
var random = getRandomNumber( " abc 12 " );
var a = random.real;
var b = random.integer;
var c = random.positive;
var d = random.negative;
demo1.innerHTML = a;
demo2.innerHTML = b;
demo3.innerHTML = c;
demo4.innerHTML = d;
}
</script>
| real number | |
| integer | |
| positive number | |
| negative number |
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