「javascript」Numberメソッドで文字列を数値に変換するサンプル

書式
Number(数値)
使用例

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EnlighterJS 3 Syntax Highlighter
<script>
const cftA = "07";
/*数値*/
console.log(Number(cftA));
console.log(typeof(Number(cftA)));
const cftB = "-45";
/*マイナス数値*/
console.log(Number(cftB));
    
/*小数点*/
const cftC = "12.8";
console.log(Number(cftC));
/*アルファベット*/
const cftD= "134abc";
console.log(Number(cftD));
</script>
<script> const cftA = "07"; /*数値*/ console.log(Number(cftA)); console.log(typeof(Number(cftA))); const cftB = "-45"; /*マイナス数値*/ console.log(Number(cftB));      /*小数点*/ const cftC = "12.8"; console.log(Number(cftC)); /*アルファベット*/ const cftD= "134abc"; console.log(Number(cftD)); </script>
<script>
    const cftA = "07";
      /*数値*/
    console.log(Number(cftA)); 
    console.log(typeof(Number(cftA))); 
    
    const cftB = "-45";
      /*マイナス数値*/
    console.log(Number(cftB)); 
    
      /*小数点*/
    const cftC = "12.8";
    console.log(Number(cftC)); 
      
      /*アルファベット*/
    const cftD= "134abc";
    console.log(Number(cftD)); 

</script>

実行結果
7
number
-45
12.8
NaN

JavaScript

Posted by arkgame