parseInt(); 轉(zhuǎn)換成整數(shù)
var a="13.9";? ?
var b=parseInt(a);
console.log(b);? 13
console.log(typeof b)? number
console.log(isNaN (b));? ? false
var a=13.9;
var b=parseInt(a);
console.log(b);? 13
console.log(typeof b);? number
console.log(isNaN (b))? false
parseInt可以使字符串轉(zhuǎn)換為數(shù)字也可以使小數(shù)點(diǎn)變?yōu)檎麛?shù)
parseFloat();? 轉(zhuǎn)換成小數(shù)
var a="1.01";
var b=parseFloat(a);
console.log(b);? ? 1.01
console.log(typeof b);? ? number
console.log(isNaN (b));? ? false
var a=5;
var b=parseFloat(a);
console.log(b);? ? 5
console.log(typeof b);? number? 帶不帶雙引號(hào)都是number
console.log(isNaN (b));? ? false
var a=.5;
var b=parseFloat(a);
console.log(b);? ? 0.5
console.log(typeof b)? number
console.log(isNaN (b));? ? false
Number();? 轉(zhuǎn)換成number類型
var a="5";
var b=Number(a);
console.log(b);? ? 5
console.log(typeof b);? number
console.log(isNaN (b));? false
toString();? ? 轉(zhuǎn)換成字符串
var a=ture;
var b=a.toString();
console.log(b);? ? ture
console.log(typeof b)? ? string
var a=12;
var b=a.toString();
console.log(b);? ? 12
console.log(typeof b);? string
console.log(isNaN (b));? false
toFixed();? 按要求保留小數(shù)位數(shù)
var a=13.95685;
var b=a.toFixed(3);? ? ? toFixed后輸入你想保留的位數(shù)
console.log(b);? ? 13.958
console.log(typeof b)? string
