JS retaining decimal points (rounding, rounding) implementation ideas and examples_javascript skills

Copy code The code is as follows: floatDecimal.html //Retain two decimal places //Function: Round floating point numbers, after the decimal point 2 bits function toDecimal(x) { var f = parseFloat(x); if (isNaN(f)) { return; } f = Math.round (x*100)/100; return f; } //The system retains 2 decimal places, such as: 2, and 00 will be added after 2. That is 2.00 function toDecimal2(x ) { var f = parseFloat(x); if (isNaN(f)) { return false; } var f = Math.round(x*100)/100 ; var s = f.toString(); var rs = s.indexOf('.'); if (rs rs = s.length; s = '.'; } while (s.length s = '0'; } return s; } function fomatFloat(src,pos){ return Math.round(src*Math.pow(10, pos))/Math.pow(10, pos); } //Rounding document.writeln("Keep 2 decimal places:" toDecimal(3.14159267) ' '); document.writeln("Force 2 decimal places:" toDecimal2(3.14159267) ' '); document.writeln("Retain 2 decimal places:" toDecimal(3.14559267) ' '); document.writeln("Force 2 decimal places:" toDecimal2 (3.15159267) ' '); document.writeln("Keep 2 decimal places: " fomatFloat(3.14559267, 2) ' '); document.writeln( "Keeping 1 decimal place:" fomatFloat(3.15159267, 1) ' '); //Rounding document.writeln("Keeping 2 decimal places: " 1000.003.toFixed( 2) ' '); document.writeln("Keep 1 decimal place: " 1000.08.toFixed(1) ' '); document.writeln(" Keep 1 decimal place: " 1000.04.toFixed(1) ' '); document.writeln("Keep 1 decimal place: " 1000.05.toFixed(1) ' ' ); //Scientific notation document.writeln(3.1415.toExponential(2) ' '); document.writeln(3.1455.toExponential(2) ' '); document.writeln(3.1445.toExponential(2) ' '); document.writeln(3.1465.toExponential(2) ' ') ; document.writeln(3.1665.toExponential(1) ' '); //Accurate to n digits, excluding n digits document.writeln("Accurate to the decimal place 2 digits" 3.1415.toPrecision(2) ' '); document.writeln("Accurate to the 3rd decimal place" 3.1465.toPrecision(3) ' '); document.writeln("Accurate to the 2nd decimal place" 3.1415.toPrecision(2) ' '); document.writeln("Accurate to the 2nd decimal place" 3.1455.toPrecision( 2) ' '); document.writeln("Accurate to the 5th decimal place" 3.141592679287.toPrecision(5) ' '); This is my HTML page.

Javascript rounds to two decimal places

Copy code The code is as follows: function count(){ //alert( "count"); var size=~~(document.getElementById("size").value); var value=0; for(var i=0;i var val=1*(document.getElementById("afterAdjScor" i).value); if(null!=val){ value =Math.round((1*(value val) )*100)/100; } } if(isNaN(value)){ value="The input must be a numeric type"; } document.getElementById( "total").value=value; } Description:~~XX: String to int 1*XX: String to float Math.round((1*(value val))*100)/100: Rounding