84 lines
2.5 KiB
TypeScript
84 lines
2.5 KiB
TypeScript
export module NumberEx {
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/**
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* 检测数字是否越界，如果越界给出提示
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* @param {*number} num 输入数
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*/
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function checkBoundary(num: number) {
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if (_boundaryCheckingState) {
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if (num > Number.MAX_SAFE_INTEGER || num < Number.MIN_SAFE_INTEGER) {
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console.warn(`${num} is beyond boundary when transfer to integer, the results may not be accurate`);
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}
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}
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}
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/**
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* 精确乘法
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*/
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export function times(num1: number, num2: number, ...others: number[]): number {
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if (others.length > 0) {
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return times(times(num1, num2), others[0], ...others.slice(1));
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}
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const num1Changed = num1.Float2Fixed();
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const num2Changed = num2.Float2Fixed();
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const baseNum = num1.DigitLength() + num2.DigitLength();
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const leftValue = num1Changed * num2Changed;
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checkBoundary(leftValue);
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return leftValue / Math.pow(10, baseNum);
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}
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/**
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* 精确加法
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*/
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export function plus(num1: number, num2: number, ...others: number[]): number {
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if (others.length > 0) {
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return plus(plus(num1, num2), others[0], ...others.slice(1));
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}
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const baseNum = Math.pow(10, Math.max(num1.DigitLength(), num2.DigitLength()));
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return (times(num1, baseNum) + times(num2, baseNum)) / baseNum;
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}
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/**
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* 精确减法
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*/
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export function minus(num1: number, num2: number, ...others: number[]): number {
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if (others.length > 0) {
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return minus(minus(num1, num2), others[0], ...others.slice(1));
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}
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const baseNum = Math.pow(10, Math.max(num1.DigitLength(), num2.DigitLength()));
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return (times(num1, baseNum) - times(num2, baseNum)) / baseNum;
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}
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/**
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* 精确除法
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*/
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export function divide(num1: number, num2: number, ...others: number[]): number {
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if (others.length > 0) {
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return divide(divide(num1, num2), others[0], ...others.slice(1));
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}
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const num1Changed = num1.Float2Fixed();
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const num2Changed = num2.Float2Fixed();
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checkBoundary(num1Changed);
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checkBoundary(num2Changed);
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return times((num1Changed / num2Changed), Math.pow(10, num2.DigitLength() - num1.DigitLength()));
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}
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/**
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* 四舍五入
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*/
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export function round(num: number, ratio: number): number {
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const base = Math.pow(10, ratio);
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return divide(Math.round(times(num, base)), base);
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}
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let _boundaryCheckingState = false;
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/**
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* 是否进行边界检查
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* @param flag 标记开关，true 为开启，false 为关闭
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*/
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function enableBoundaryChecking(flag = true) {
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_boundaryCheckingState = flag;
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}
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} |