1:把数字转换为字符串的方法
var string_value = String(number);
string_value = number.toString();var n = 17;
binary_string = n.toString(2); //Evaluates to "10001"
octal_string = "0" + n.toString(8); //Evaluates to "021"
hex_string = "0x" + n.toString(16); //Evaluates to "0x11"var n = 123456.789;
n.toFixed(0); //"1234567"
n.toFixed(2); //"123456.79"
n.toExponential(1); //"1.2e+5"
n.toExponential(3); //"1.235e+5"
n.toPrecision(4); //"1.235e+5"
n.toPrecision(7); //"123456.8"