javascript - javascript : casting int to char trouble

Question

I have a small script that read delta X and Y of a joystick and next cast they into character:

var a =deltaX.toString();
var b =deltaY.toString();
outputEl.innerHTML  = '<b>Result:</b> '
    + a
    + b;    
var comando = a + b ;

the trouble is I need number lower than 10 and -10 , to be 2 characters , so for example 5 , to be 05 . what's should be a good way to add the zero in the numbers lower than 10 and -10 ?

Answer 1

var a;

if (deltaX < 10) {
  // one digit
  a = '0' + deltaX;
} else {
  a = deltaX.toString();
}

请注意，这不处理负面部分，但我正在展示概念证明。由于您的数字非常小，您可以使用简单的if语句填充，而不是使用密封方法填充零。

Answer 2

您可以通过查看长度属性来使用三元运算符（内联 if）：

outputEl.innerHTML  = '<b>Result:</b> '
            + a.length > 1 ? a : '0' + a
            + b.length > 1 ? b : '0' + b;