Js substr,substring,slice intercepting string similarities and differences

An overview of the

Substr or substring can be used to slice a string. They can both accept two arguments. The first argument is the position at which the string is truncated, and the default is 0. Github.com/fanxuewen/e…

Pass only the first parameter

When the first parameter is positive, they are indistinguishable

let str='Good good study, day day up';
console.log('substr---:',str.substr(2));
console.log('substring:',str.substring(2));
console.log('slice----:',str.slice(2))
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let str='Good good study, day day up';
console.log('substr---:',str.substr(-2));
console.log('substring:',str.substring(-2));
console.log('slice----:',str.slice(-2));
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Two, both parameters pass

If both parameters are positive and the second is greater than the first. Substr is truncated from where the first argument begins. The second argument represents the length of the truncation. The substring and slice parameters represent the index of the intercept location, including the start but not the end

let str='Good good study, day day up';
console.log('substr---:', STR., substr (2, 4)); console.log('substring:', STR. The substring (2, 4)); console.log('slice----:', STR. Slice (2, 4));Copy the code

small

let str='Good good study, day day up';
console.log('substr---:', STR., substr (2, 1)); console.log('substring:', STR. The substring (2, 1)); console.log('slice----:', STR. Slice (2, 1));Copy the code

Other cases to verify……..