判断是否是正实数
function isNumber(val){
//to do
}
isNumber(0) //true
isNumber(1.31) //true
isNumber("1.32") //true
isNumber("3r") //false
isNumber("1.3.4") //false
isNumber("0") //true
isNumber("107") //true
isNumber("-1.32") //false
//to do
}
isNumber(0) //true
isNumber(1.31) //true
isNumber("1.32") //true
isNumber("3r") //false
isNumber("1.3.4") //false
isNumber("0") //true
isNumber("107") //true
isNumber("-1.32") //false
...全文


